Thanks for sharing with us the details, @Tevan.
CRM may have updated its application that makes QuickBooks unable to sync with it accordingly. To make sure that this is taken care of, I'd suggest contacting CRM to inquire if they have recently made changes with their software. You can visit their website to find support.
Also, you can go to this site to get a free consultation with our Bookkeepers: Live Bookkeeping.
Share with us after reaching CRM support if you have more questions. I'll keep my notifications open. Keep safe and well!