I reckon Nasdaq was freaked out by the skewed market depth- so many buyers and barely any sellers, or sellers putting orders in at ridiculous prices. It's clear if you review the bookview sceenshot I posted earlier.
From the info above it seems that Sezzle simply needs to prove that there will be enough shares available on offer (not like last night) aka "facilitate proper price discovery"
imo sezzle need to fix this, not try and get asx holders to convert cdis to common stock, or maybe they could've given instructions on how to convert, ahead of the listing night.