Also have this problem, commenting in hope for a reply :'o

Ive also noticed this too and also on aberration the craft tab vanishes and I need to pick up the table and place it back again

You can't craft compounds at the AA Workbench because the only crafting station flags it has are those relating to PC, smithy, and fabricator. If the engram can be crafted either by hand, the smithy, or the fabricator then the AA Workbench can do it as well (including repairs). Even if it was flagged as a mortar/pestle I wouldn't suggest using it since the AA Chemistry Station is even better than the S+ version since the AA version includes built-in refrigeration while the S+ does not.