A PC library is synced to an Id which may or may not be part of the issue but I think it might be because this has never happened before and these libraries have only been synced around a week. The issue is I kept thinking that music added to the PC playlist of the month was missing but chalked it up to bad memory. Then last night I added an album on the PC using drag and drop from File Explorer into the Playlist (method I have used for 5 years) and went to the Id to play the music and it wasn't there. I went back to the PC and indeed it was gone. I added it back and a couple minutes later it disappeared again.
After adding it back about 10x it finally stayed. So, I was thinking maybe this was some kind of one-off. It happened again the next day with a different album. I even have a video taken with my phone of the screen moving and the recently added songs disappearing just in case you think I am nuts and this cannot be.
Video link to 9mb file that got rotated 90 degrees if anyone really wants to see MC blink and all the files from one album disappear.
https://ufile.io/08lpqb3wAnother change I made a couple hours before seeing this issue was trying to set-up Port Forwarding using my best guess how to do it for MC so I could listen to music on an Android phone when in the car.
Could that cause this? Edit - deleted the Port Forwarding entry on the router and the problem continues.
Is this a known issue? Is there something I can do? Could it be some kind of system lag I've never dealt with before around auto-importing files and libraries syncing in the background?