I found a problem. When I change the material of the interior wall, I drag the slider and apply it to all walls, but the material does not change. It works only when the slider is slid to the minimum value and applied to all walls. Is this a bug or am I operating it incorrectly?
Change the material of the interior wall
You are correct, there is actually a bug. The quick workaround is to click on a different wall, select a texture, then click "apply to all walls", then the slider works for all walls again.
I will investigate the bug and keep you posted here. Thanks for reporting.
I have sent you a patch by email via wetransfer