I've not had a chance to test this, but based on the troubleshooting everyone else has done I'm assuming it's an LSPDFR bug. Perhaps something has been changed or deleted around apartments or maybe a hook or pattern has failed.
I'm not too familiar with the apartment system, so even if I have a chance to look at this I'm unlikely to fix it quickly.
With the festive season there is probably going to be a delay around fixing this if it's an LSPDFR bug. I can only speak for myself but I will have probably no free time in the coming days, the situation is probably similar with the rest of the development team. Sorry about that.