Same thing happened to two different SPs I've created from scratch this year as well.
The issue happened right around end of June/beginning of July of their first season for both characters. I've tried simming them to the end of the season but no luck. I didn't try asking for a trade but I might as well try that as well. And the only reason i started that 2nd SP was the hope the bug wouldn't carry over to the new character, lol.