Aha! Makes sense. Now that I’ve actually read the information you provide for setting up the ST (duh, who reads the manual! 
), this makes perfect sense. The exFAT format may be more compatible with a linux machine. This could explain why the drive works perfectly with the Windows Roon server but has some issues with the ST.
I’ll have time to do all this late next week and I’ll report back here on the outcome.