I have seen similar issues with the iClould sync between my PC and iphone/iPad app iCloud sync issues
I keep close look at my iCloud drive to make sure there are no duplicated files and all files are synced, otherwise I kill the iCloud task and restart iCloud drive. I also kill (swipe up) on the iphone/iPad app every time before I use it to make sure it starts from a fresh state and syncs all updated files.
I also just logged an issue with the “recent files” plugin after being able to duplicate a sync issue issues with iCloud sync · Issue #33 · tgrosinger/recent-files-obsidian · GitHub