IP allows you to change the quote number, The first number is QU01. Lets say you change it to QU09. It lets you save it but then when you create a new one the numbering restarts to QU01. If you keep creating quotes, eventually it will create a duplicate quote with number QU09. Everything is fine until you add a product to it. It does not let you save the products you added. It does not give you an error. It just keeps spinning and when you refresh it the products are not there.
My solution was to duplicate the quote, which assigns it a new number, then it lets you save it.
I think IP should either not allow quote renumbering or not restart the numbering. If you change it to QU09, make the new ones start at QU10.
I just noticed there is a post about this same issue from June…