Since new update I can't use my own 3.5 headphones with the adapter
Is it possible this isn't connected to the recent update but instead the adapter or earphones have failed in some way !
Can you perhaps try your earphones on another device and also try the adapter too ?
Use a torch to make sure the port on the phone is clear of debris.
Is it possible to try another set of earphones in your phone and if possible another adapter.
Current Phone > Samsung Z Fold³ 5G.