I also have the issue of being unable to import new music (MP3 and FLAC files) using 23.0.36. I haven't tried 23.0.41 since I'm set to the "Stable" channel and 23.0.36 is what is currently offered there.
I'm using Windows 7 64 bit that is up to date with Microsoft patches.
Normally it would have auto-imported the new music shortly after MC was started, but it didn't. So I used Tools->Import->Import from a single folder, pointed at my Music directory to tell it to import and it seems to simply not find any new music to import, no actual error message per say.
I tried uninstalling 23.0.36 and reinstalling the version I had prior 23.0.22, and it does import the new music just fine. But if I allow it to update to 23.0.36 again, it will again fail to import additional new music.
Additionally under 23.0.22 it says I have a .mp3 file that was previously determined to be bad, but under 23.0.36 it does not mention that file. (I believe the file really is bad so I think .36 just isn't really scanning for new files like it says/thinks it is).
I also still have 22.0.108 installed and it it too correctly imports new music mentioning the bad file, while 23.0.36 does not import anything. the difference in the file count between the two versions 22 and 23 is exactly 10 files (the amount of new music I added to the Music directory to be imported)
The fact that the earlier build 23.0.22 does work, but up re-updating to 23.0.36 doesn't, I think rules out any issue of permission change on the Music directory being the cause of the issue or any other changes to the operating system causing the issue since no other changes were made between the tests.
Since others have reported this issue with 23.0.41 also, I don't think I feel any need to attempt trying that release.