I have a new build for you to try. This one is Qt 5.12.9 based (since the experimental Qt6 did not help). It will write debug output when you try to save Controls in Saved Searches.
I was able to sign this one as it is Qt5 based.
https://github.com/kevinhendricks/Bu...or_sigil_1.0.0
Download: Sigil.app-1.9.0-Beta-Mac.txz
Please copy it to your Desktop and unpack it there.
Then open Terminal.app and enter the following commands:
cd
cd Desktop
export SIGIL_DEBUG_LOGFILE="sigil_debug_log.txt"
open ./Sigil.app
When it opens (you might have to fight with GateKeeper to get it to open before trying this) then go to Saved Searches and try to edit a controls field. Then use the X to close the Controls dialog.
Then exit out of Sigil.
You should then see a file on your Desktop called: sigil_debug_log.txt
Please open it in any text editor and paste its contents here so that we can see if the routine to actually save the edited controls is even being tried.
Thanks