@jonas - sorry for all the replies --

I figured out how to solve the issue. I vaguely remembered skimming past a comment somewhere that the flatpak version of Strawberry had some kind of issue (and I had downloaded the flatpak). So I uninstalled that, and got the 'true' version via the terminal.

This time, when I added my external drive to the directory, the file path actually looked normal... so that was a good sign. I rebooted the pc, ran Strawberry... and sure enough -- the library remained, and I was able to play songs as expected.

So, TL;DR for anyone stumbling onto this thread with the same issue I had - uninstall the Strawberry flatpak and get it direct from the terminal. I followed the steps on this link: https://linuxcapable.com/how-to-install-strawberry-music-player-on-linux-mint/
... and get the normal/stable version.

@jonas - Rats -- After reboot, the library still appears to be there, so I got excited for a minute... but Strawberry isn't able to play any of the songs.

"Resource not found" error message.

@jonas - Okay, I just updated those options and Strawberry is rebuilding the library now. I'll reboot the pc soon and see if everything sticks this time. Thanks!

Just for clarity, I did finally think to check.. and that file-path for the library seems to be culprit.

/run/user/1000/doc/xxxxxxxx/Music
(the x's are some random-to-me group of numbers and letters)

Which is a convoluted path to my external drive...

And that 'xxxxxxx' section changes upon reboot... when I have to re-add the library, it's a new set of letters/numbers. It all works fine until reboot.

PS - the external drive is set to auto-mount to the same spot, so that shouldn't be an issue.

Hello!

This issue has been driving me insane --

I have an external drive with my entire music library connected to a Linux Mint PC. I point the Strawberry library to the appropriate drive/folder... and everything loads as you'd expect. Everything continues to work, even if I close Strawberry and re-open it.

Once I need to reboot the actual PC, however... the next time I open Strawberry, the entire library is lost. I have to re-add the drive/folder into the collection, and wait for it to recompile (and also lose things like fixed album images as well.)

The odd thing is that the folder path is strange, once added:

/run/user/1000/doc/......

Which is nothing like the the simple mount point. The mount is more like:

/usbmedia01

The closest thing to a similar issue I've seen posted here, is the last reply by DGG at this thread:
https://forum.strawberrymusicplayer.org/topic/1473/why-is-a-collection-rescan-required-after-a-restart/6

Hoping some of the experts know what I'm doing wrong!

Thanks!