Problem w/ Downgrade to 3.3.3 using Mission Plannner

I am helping a client that has loaded new firmware onto their PixHawk and now wants to revert back to 3.3.3 so PIDs match and they can fly again.

I’ve used Mission Planner for years but have been away for awhile: I can’t seem to find the alternate firmware choices nor any Internet chatter on why 3.3.3 would no longer be a firmware option.

The easy fix for this client is to get them back to 3.3.3 and on mission. The inconvenient option would be to accept current firmware and rewrite PIDs since that involves international shippping and time.

Any help or news will be appreciated! Thanks!