If the charging light did come on properly as if it’s charging like normal, then it’s possible that it’s just the receiver/wiring harness that went bad. Or it can be as simple as a wax blocking issue. Usually 9 out of 10 times my aids would just quit suddenly were due to excessive wax issues. I would check for wax first or try to replace the wax filter.
If that doesn’t help, another thing you can try is to swap the right receiver on your left aid to see if that works. If that works, then you know that it’s the receiver/wiring harness that has a problem. Sometimes the connection at the base of the receiver wiring harness to the aid is loose and just needs to be removed and reconnected to restore the connection.
Removing the receiver/harness from the aid is simple, but you need to know how to do it properly. You can easily find instruction on how to do it on YouTube.