When I added Exordium to my modpack, the names of items were showing up where they would with a normal hotbar, which means with double hotbar it now ends up behind the second hotbar. This is not an issue if the mod is not installed.
Without Exordium

With Exordium

Tested in fabric 1.20.1

Either try turning off hotbar buffering in the options, or remove Exordium.

Well that was fast! Disabling hotbar buffering indeed fixed the issue. Thank you!

Well that was fast! Disabling hotbar buffering indeed fixed the issue. Thank you!

That also disabled whole optimization of hotbar from Exordium btw

Thats the point? Exordium is only made for Vanilla. When mods change stuff and it doesn't work with that, turn it off or remove Exordium.