Songs play in iTunes library and say they sync to iPhone, but don't transfer to iPhone

thanks for replying. hovering over the ! doesn't have anything pop up when I try that. I do song info and it looks pretty normal as well. the !s only show up when I'm on iTunes, looking at what's on the iPhone when plugged into the PC. I know what you're talking about, I've seen !s when iTunes can't find the source of file when I'm looking at the main library and trying to play a song. That's not the issue because the songs are playing from the library. When I go to "on my device" when I'm on iTunes, I get the !s when trying to play a song that looks like it's on my phone, but it's not. I'll attach pics to hopefully demonstrate.

above is library, below is showing what should be on the phone. Should mention I have latest iOS and iTunes versions (and iPhone 14)

I could add too that these songs used to sync fine to my phone, but when I changed them to a different folder on pc, they no longer worked to sync (they got the ! on the library for iTunes not being able to find them). Even though I re-linked the files to itunes and deleted the versions that had the !s, the versions that have the ability to play from iTunes library still won't transfer to my phone. The only thing left I haven't tried is resetting it and restoring from backup, but I'm worried it will just restore the same error in the backup, since it's backed up the incomplete playlist with songs on the phone that have !s

Thank you so much. I just backed it up, restored as new, restored from backup and that got it to work. Only took a few hours but glad the nuclear option finally actually worked to solve this weird issue

As luck would have it, the issue came back up again when I updated to the latest iOS security update. I'm guesing that's originally caused the issue. Instead of restoring from backup this time, also since there were fewer songs that needed fixing, I figured out one fix is to change information about the song in library and re-sync. That causes it to be able to sync properly for some reason if the info is new. Maybe one fix for more songs in a library could be adding a comment to every song in the library that's having issues and re-sync and they should all go through since the file is so slightly different.

the best workaround I can come up with is using home sharing. The songs play from my phone off of the PC home sharing library, but isn't actually downloaded onto the phone. Very frustrating