Rekordbox keeps crashing when trying to create new playlist; can't delete playlists either

Using Rekordbox 6.6.8 with Windows 10/Lenovo ThinkPad T470

Rekordbox database is stored on an external 4TB USB3.0 HDD

Whenever I try to create a new playlist in my collection (25k+ tracks) Rekordbox is crashing/not responding/apparently stuck in an infinite loading loop. It worked until just now since I already created several playlists today.

Deleting old/unused playlists didn't help, the issue still occurs. Also deleted playlists seem to reappear when Rekordbox is restarted, even if I quit Rekordbox without it crashing/becoming unresponsive and reboot the PC in between).

There are still system resources available as according to the Task-Manager both my CPU and RAM are at close to 60% capacity (40% CPU are being used by RekordboxAgent). Deactivating Windows real-time Malware protection did not help either. Issue still persists after rebooting.

Edit: After rebooting several times as well as renaming a playlist that contained the string '( "J*' minus single quotes to something without those special characters everything went back to normal. Might want to investigate, could be a problem with your XML-processing.