My wife and I tried to use Monica for many months in the past but had to give up because of the incredibly buggy CardDAV implementation when using iOS. Now that this has come out it seems the issue (https://github.com/monicahq/monica/issues/6175) was ignored likely because of all this work.
Have improvements been made with this in the new version?
Safari seems to have been getting more developer attention this last year. This is good but also has resulted in a number of bugs and regressions as they move fast. Same is happening on Chromium.
I likewise have been involved in a similar bizarre bug. We wrote up a very detailed report with a reduced test case but sadly it has not received much attention. https://bugs.webkit.org/show_bug.cgi?id=247020