My MAc Studio workflow has always been as follows.
Capture One Edit With…Photo AI
C1 Creates a .tif which opens in Photo AI
On Save I have Overwrite File selected which updates the original .tif in C1 keeping the same filename.
In 1.2.7 I noticed that although the effects were visible in Photo AI on a Save Overwrite the effects were not written to the file.
As a trial I added the applied filters to the original filename and they did not get added.
I uninstalled Photo AI and re installed it. The save Overwrite still does not update the original file but add applied filters to filename now works properly.