Is there a way to fix the uneven wiper blades that don't bottom out together on the frame when switched off? It feels like one blade has some play in it when you swivel it back and forth on it's axis?
They mount to the shaft with a splined fitting, yours may be worn. Might have to get new arms. If it's the shaft itself that is worn it's a bit more challenging. You'd need to replace the shaft.
If the splines are stripped, a shim of some kind can tighten up the fit. I had an old Blazer with a loose stripped wiper arm. A layer of masking tape held tight for several years before the vehicle was scrapped.