I have the items to trade in this screenshot but the green arrow doesn't show up.

Can't reproduce, trading a compass works well for me. Still assuming the compass was enchanted which prevents trades.

The compass was not enchanted but had some tags from Quark

The check shouldn't be done with tags since vanilla seems to not care about them

Probably a problem with enchanted items - enchanted items are excluded from trades. Need to check if compasses are detected as "enchanted" even when they are not.