15.3.0 Unsaved changes prompt using Inline editing mode on a block list

[MrHutmat]

Which Umbraco version are you using? (Please write the exact version, example: 10.1.0)

15.3.0-rc.preview.178

Bug summary

If you have Inline editing mode on a block list that has a nested block list inside of it, you will get prompted about unsaved changes if you open up the block list editor.

I tested this on the v15/dev branch.

Specifics

20250225-1213-07.5099765.mp4

ETHotelDateRateItinerary
- Has a nested block list - HotelDateRatePriceMenu

ETHotelDateRatePrice
- Has 3 Strings

Steps to reproduce

1. Create an element type with 3 string properties (ETHotelDateRatePrice).
2. Create a Block List data type (HotelDateRatePriceMenu), and add the ETHotelDateRatePrice element.
3. Create a new element (ETHotelDateRateItinerary), and add a text string property and a HotelDateRatePriceMenu Block list property.
4. Create a new Block list data type (HotelDateRateItinerary), and should use the ETHotelDateRateItinerary element.
5. Create a doc type and allow it as root.
6. Make a property that uses HotelDateRateItinerary and one that uses HotelDateRatePriceMenu.
7. See the different behaviors with the examples from underneath.

If HotelDateRatePriceMenu has "Inline editing mode" and HotelDateRateItinerary doesn't:
- Nothing behaves out of order.

If HotelDateRatePriceMenu doesn't have "Inline editing mode" and HotelDateRateItinerary doesn't either:
- Nothing behaves out of order.

If HotelDateRateItinerary has "Inline editing mode" and HotelDateRatePriceMenu doesn't:
- We get the unsaved work warning when we navigate away.

If HotelDateRateItinerary has "Inline editing mode" and HotelDateRatePriceMenu has it:
- We get the unsaved work warning when we navigate away.

So if a block list that has a block list nested inside of it has "Inline editing mode" turned on, you get this behavior.

Expected result / actual result

Since I just opened the block list and didn't make any edits, I wouldn't expect there to be changes made that haven't been saved.