Room "division fails" in the app

X50 Ultra detected two adjacent rooms as one. Now when I'm trying to manually divide the room, i keep getting this error message: "The end of the division line is not on the boundary of the division zone; division fails".

Regardless of how much I try to exactly adjust the end of the division line, try to put it on different locations, etc, I keep getting this error.
Please advise.
file:///C:/Users/anazem/AppData/Local/Temp/share_2114417731340795489.png

I was initially getting the same error too, then I tried to simply move the line that shows up when I click divide without resizing it, and that did the trick. It created a new room by splitting the one big room created earlier.