Here’s a temporary workaround. You could do a CHGMSGQ on the message queue and change the MSGQFULL parameter to *WRAP**.
This option will lop off the old entries to make room for new ones.
I say temporary because you should always have a log of what was saved and restored. How many libraries are you restoring?
**-*PRTWRAP would be a better option as you will not lose what is already in your job log. –Billy