editing assistant rules causes loss of selected tiles

[viraelin]

version 1.5.3, AppImage

problem:
In the Assistant tool, there is the ability to multi-select tiles for a given tile. This selection is lost when editing the rules, and must be manually done for every tile again. This is illustrated via the color distinction of tiles below.

before (good):

after editing and saving rules (bad):

steps to repro:

1. open project
2. click "RULES" in IntGrid layer
3. click "EDIT" in rules group
4. click "UPDATE RULES" in popup dialog

to restore to how it was at the beginning:

1. click "EDIT" in rules group
2. click tile in left pane
3. click and drag tile in right pane (orange + blue)
4. repeat for other tiles

minimal repro project:
repro.zip