Haven't had any issues with this addon in SL up until I realized 'Unstable Affliction' no longer resizes. In previous expansions, it always did so for me, and I was so used to seeing the large UA debuff that I have died in arena matches this expansion, not realizing there was a UA debuff on myself or others (since it's just showing normal size now).

I attempted to move the priority to 100 and resize to 100 but still did not notice any changes. I have UA checked in 'Warning Debuffs' as well.

Same. No matter what I do I can not get UA to show properly. I think the spell ID might have changed in Shadowlands as the whole spell got reworked.

The Addon has the wrong Spell-ID for UA. The correct one is "316099". If you go to Retail.lua you can add it on the bottom of the list to where addon.WarningDebuffs is assigned (line 31 on my local copy). Make sure to add it at the bottom (below the other, outdated UA spell id's), because then the correct debuff will override the other ones (same name) when the respective array is being created.
This fixes the fact that UA gets hidden while a big debuff icon is displayed. I think it should also fix the issue mentioned by the OP, because there is also a slider for "Warning Debuffs" in the settings. I might test this real quick to check if it also fixes this error, though. I am not sure.

Hello @Mercious did you test it yet? I have put the spell ID "316099", I will test it to see if it works.

Should we add the new ID under the priority debuffs section also? Line 44

Thanks in advance

1Banz