We have been having a number of users requesting to use older versions of MC as they suspect that the issues they are experiencing are with the slicer. We don't usually change much to the core slicer itself and more often than not, changing the slicer version does not improve results.
When moving the printer, the Z gantry could become offset and cause all sorts of odd printing issues. Upgrading the software at the same time is coincidental and the last thing I would suspect. Next on the list would be to ask if you have a ruby nozzle, those fracture and chip all the time if they get hit or run into the plate and can cause more printing issues that look like under extrusion, ringing, and shifted layers.