There appears to be a similar issue with the Atom & ATV… I would put a ticket in but that will disappear into the ether and get no updates going forward.
If I Perform a workout in erg… End work out and continue in free ride and you are stuck in the gear you are placed in… zwift won’t respond to gear changes.
This has only been in place a few weeks / month or so… so 1.15 or 1.16.
Only way to fix this is to kill zwift and power cycle the atom and basically start again.