Ah well, I was on MiBox S 9.0 Pie before and it was running fine (the pie version which I updated earlier this year, probably during February?)
I only got myself into trouble with PLEX right after I updated the latest patched version of Pie on my MiBox S like 2 days ago.
Some of my other streaming app for my telco doesn’t work either, no luck even after trying with multiple sideloaded versions.
Ah well… at least now I can still use Plex with the older player (changed in client setting)