There is a long-time bug with Halo of Arlyse causing Ice Armor to stop proccing certain things after changing floors, using a potion, or picking up an item.
They fixed it for some things, but as of Sep '22 (the last time I tested it) it was bugged with Tal’s: Halo of Arlyse not triggering Meteor w/Frozen Storm rune - #2 by TinneOnnMuin-1187
If the old bug is still happening, the reason you didn’t observe it in the clip you posted is because you cast Ice Armor after entering the zone.
I will see if I can still reproduce it.