@kjjarv
Oddly enough, this only happens to checks. The invoice number field on invoices seem to work fine. It jumps to the next sequence. Perhaps there's an ongoing issue with the Check no. field, so I would follow-up with support on that.
I managed to work this around by refreshing the Check page entirely after clicking Save and new, or just exiting out of the page, then going back to the Check creation page. It should show the next sequence. A bit frustrating on my part.
JPNE
JPNE-IBR