Just had a second look at the situation and I find it works properly apart from 21.5E not showing up if I press theSAT LIST button.
But the All Satellites Channel List does show the 21.5E Channels and I can select and view them.
It also shows up in the Installation >> Satellite List Menu!
Weird.
I've decided to leave it for now: I love quirks, me.
PS: Reloading the TP_Prog file I had Dumped prior to the "Upgrade" process makes no difference, so it did indeed keep the old file uncorrupted. The bug seems to be in how it displays TP_Prog contents.