Where is the client's bank located?  In Oregon?  There seems to be a special BofA number for Oregon that starts with a 3.  Is there a box to check where you have to verify that the funds are not eventually going to be sent out of the country?  I think this could be a problem with the Oregon Department of Revenue, not with the bank.  But since it's in North Carolina, I think calling them would be useless.  

Why is this your problem, anyway?  Have you suggested to your client that the next time they go into the bank, they ask if anyone else has noticed this?  Of course, if the clients are not in Oregon, they may be the only ones affected.  

If watching the mail for a paper check is the worst thing they have to do in 2020, they will have a good year.  Is it Oklahoma that sends a debit card instead of paper checks? Now that would be inconvenient.