Error on assignment: rpc error: following README instructions

[rib]

Just to mention that when I try deploying this demo based on the README instructions (including using 4x n1-normal-4 nodes) then the web client shows this error after a while of trying to find a match:

An error has occured, refresh to continue:
Error on assignment: rpc error: code = Unknown desc = Error streaming assignment: rpc error: code = Unavailable desc = transport is closing

The only change I made was to set REGISTRY=eu.gcr.io since I'm based in the UK.

The status for all the workloads looks Ok/Running for everything so no obvious deployment problems.

Looking at the browser console, this is the full error and backtrace for the wasm client:

2019/12/10 03:09:14 A fatal error has occured:An error has occured, refresh to continue:
 Error on assignment: rpc error: code = Unknown desc = Error streaming assignment: rpc error: code = Unavailable desc = transport is closing

RuntimeError: index out of bounds client.wasm:110454:1
    lock http://34.89.84.139/static/client.wasm:110454
    chanrecv http://34.89.84.139/static/client.wasm:69685
    chanrecv1 http://34.89.84.139/static/client.wasm:68990
    fsCall http://34.89.84.139/static/client.wasm:1536611
    Write http://34.89.84.139/static/client.wasm:1531945
    Write http://34.89.84.139/static/client.wasm:1692553
    Write http://34.89.84.139/static/client.wasm:1724823
    Output http://34.89.84.139/static/client.wasm:1926154
    Fatal http://34.89.84.139/static/client.wasm:1933014
    fatalError http://34.89.84.139/static/client.wasm:8523534
    func1 http://34.89.84.139/static/client.wasm:8568541
    wasm_pc_f_loop http://34.89.84.139/static/client.wasm:847530
    wasm_export_resume http://34.89.84.139/static/client.wasm:847499
    _resume http://34.89.84.139/static/wasm_exec.js:544
    _makeFuncWrapper http://34.89.84.139/static/wasm_exec.js:555

RuntimeError: indirect call to null client.wasm:847530:1
    wasm_pc_f_loop http://34.89.84.139/static/client.wasm:847530
    wasm_export_resume http://34.89.84.139/static/client.wasm:847499
    _resume http://34.89.84.139/static/wasm_exec.js:544
    _makeFuncWrapper http://34.89.84.139/static/wasm_exec.js:555

fatal error: semacquire not on the G stack wasm_exec.js:47:14

runtime stack: wasm_exec.js:47:14
sync.runtime_SemacquireMutex(0xc58004, 0x900000000, 0x1) wasm_exec.js:47:14
	/golatest/src/runtime/sema.go:71 +0x2 wasm_exec.js:47:14
sync.(*Mutex).lockSlow(0xc58000) wasm_exec.js:47:14
	/golatest/src/sync/mutex.go:138 +0x24 wasm_exec.js:47:14
sync.(*Mutex).Lock(0xc58000) wasm_exec.js:47:14
	/golatest/src/sync/mutex.go:81 +0x7 wasm_exec.js:47:14
log.(*Logger).Output(0xc58000, 0x2, 0x1426090, 0x30, 0x0, 0x0) wasm_exec.js:47:14
	/golatest/src/log/log.go:162 +0x5 wasm_exec.js:47:14
log.Println(0x796fe8, 0x2, 0x2) wasm_exec.js:47:14
	/golatest/src/log/log.go:326 +0x3 wasm_exec.js:47:14
main.NewWrappedWebSocket.func4(0x7ff8000100000d1d, 0xf159f0, 0xfc3e40, 0x1, 0x1, 0xf159f8, 0x7970e8) wasm_exec.js:47:14
	/go/src/github.com/laremere/space-agon/client/client.go:504 +0x3 wasm_exec.js:47:14
syscall/js.handleEvent() wasm_exec.js:47:14
	/golatest/src/syscall/js/func.go:90 +0x24 wasm_exec.js:47:14
runtime: unexpected return pc for runtime.handleEvent called from 0x77a0a0 wasm_exec.js:47:14
stack: frame={sp:0x7970e0, fp:0x797118} stack=[0x795538,0x797138) wasm_exec.js:47:14
0000000000796fe0:  0000000000e59250  000000000006f480 wasm_exec.js:47:14
0000000000796ff0:  00000000001bbaa0  000000000006f480 wasm_exec.js:47:14
0000000000797000:  0000000000fc3e50  0000000017a10024 <syscall/js.handleEvent+36> wasm_exec.js:47:14
0000000000797010:  7ff8000100000d1d  0000000000f159f0 wasm_exec.js:47:14
0000000000797020:  0000000000fc3e40  0000000000000001 wasm_exec.js:47:14
0000000000797030:  0000000000000001  0000000000f159f8 wasm_exec.js:47:14
0000000000797040:  00000000007970e8  00000000130d0001 <runtime.runtimer+1> wasm_exec.js:47:14
0000000000797050:  0000000000c360b0  01000000185a000d wasm_exec.js:47:14
0000000000797060:  000000000000009e  0000000000000000 wasm_exec.js:47:14
0000000000797070:  0000000000000001  7ff8000100000610 wasm_exec.js:47:14
0000000000797080:  7ff8000100000d1d  7ff800010000060f wasm_exec.js:47:14
0000000000797090:  0000000000e45b90  0000000000fc3e40 wasm_exec.js:47:14
00000000007970a0:  0000000000f159f8  0000000000f159f0 wasm_exec.js:47:14
00000000007970b0:  0000000000f159e8  0000000013410004 <runtime.isSystemGoroutine+4> wasm_exec.js:47:14
00000000007970c0:  0000000010a50000 <runtime.handleAsyncEvent+0>  7ff80001000005fd wasm_exec.js:47:14
00000000007970d0:  0000000000f15a00  0000000010a40007 <runtime.handleEvent+7> wasm_exec.js:47:14
00000000007970e0: <00000000125a002b <runtime.goexit0+43>  0000000000000000 wasm_exec.js:47:14
00000000007970f0:  0000000000000000  0000000000000000 wasm_exec.js:47:14
0000000000797100:  0000000000000000  0000000000c00d80 wasm_exec.js:47:14
0000000000797110: !000000000077a0a0 >00000000139f0001 <runtime.mcall+1> wasm_exec.js:47:14
0000000000797120:  0000000000c00a80  0000000000797160 wasm_exec.js:47:14
0000000000797130:  0100000000000000 wasm_exec.js:47:14
<empty string> wasm_exec.js:47:14
goroutine 1 [chan receive, 1 minutes]: wasm_exec.js:47:14
main.main() wasm_exec.js:47:14
	/go/src/github.com/laremere/space-agon/client/client.go:41 +0x6 wasm_exec.js:47:14
<empty string> wasm_exec.js:47:14
goroutine 3370 [runnable]: wasm_exec.js:47:14
runtime.handleAsyncEvent() wasm_exec.js:47:14
	/golatest/src/runtime/lock_js.go:230 wasm_exec.js:47:14
runtime.goexit() wasm_exec.js:47:14
	/golatest/src/runtime/asm_wasm.s:428 +0x1 wasm_exec.js:47:14
<empty string> wasm_exec.js:47:14
goroutine 152 [waiting]: wasm_exec.js:47:14
syscall/js.Value.Call(0x7ff800010000000a, 0xc28020, 0x12d846, 0x5, 0xc7e460, 0x6, 0xa, 0xa, 0x7d0008) wasm_exec.js:47:14
	/golatest/src/syscall/js/js.go:390 +0x3 wasm_exec.js:47:14
syscall.fsCall(0x12d846, 0x5, 0xc43ca8, 0x5, 0x5, 0xe6, 0xf15988, 0x10a0478, 0x0) wasm_exec.js:47:14
	/golatest/src/syscall/fs_js.go:496 +0xc wasm_exec.js:47:14
syscall.Write(0x2, 0xd48000, 0xe6, 0xf0, 0xd48000, 0x779a00, 0xe) wasm_exec.js:47:14
	/golatest/src/syscall/fs_js.go:417 +0xd wasm_exec.js:47:14
internal/poll.(*FD).Write(0xc36180, 0xd48000, 0xe6, 0xf0, 0x0, 0x0, 0x0) wasm_exec.js:47:14
	/golatest/src/internal/poll/fd_unix.go:268 +0x22 wasm_exec.js:47:14
os.(*File).write(...) wasm_exec.js:47:14
	/golatest/src/os/file_unix.go:280 wasm_exec.js:47:14
os.(*File).Write(0xc0c028, 0xd48000, 0xe6, 0xf0, 0xe5, 0xd48000, 0x14) wasm_exec.js:47:14
	/golatest/src/os/file.go:153 +0xf wasm_exec.js:47:14
log.(*Logger).Output(0xc58000, 0x2, 0xc8c1c0, 0xd1, 0x0, 0x0) wasm_exec.js:47:14
	/golatest/src/log/log.go:181 +0x13 wasm_exec.js:47:14
log.Fatal(0xc43f30, 0x2, 0x2) wasm_exec.js:47:14
	/golatest/src/log/log.go:331 +0x3 wasm_exec.js:47:14
main.fatalError(0x1c4920, 0x145f420) wasm_exec.js:47:14
	/go/src/github.com/laremere/space-agon/client/client.go:431 +0xf wasm_exec.js:47:14
main.(*client).matchmake.func1(0xe4e280, 0xe45bc0, 0xc58690) wasm_exec.js:47:14
	/go/src/github.com/laremere/space-agon/client/client.go:227 +0x1d wasm_exec.js:47:14
created by main.(*client).matchmake wasm_exec.js:47:14
	/go/src/github.com/laremere/space-agon/client/client.go:215 +0x13

In the frontend container log I see this error:
"time="2019-12-10T03:15:21Z" level=error msg="failed to get ticket bnngr1m5r33t2q6b852g when executing get assignments" app=openmatch component=statestore.redis error="rpc error: code = NotFound desc = Ticket id:bnngr1m5r33t2q6b852g not found"

Hoping it looks familiar and there's a simple thing I'm overlooking :)