We've had to start using the new account as our undeposited funds account, and we had to manually move every transaction to the new account until the old one had a balance of $0 since we couldn't choose it as an option. It's not just titled "Old Undeposited Funds" and contains a history of everything that moved in and out of there prior to this issue starting.

It was a huge mess, but that was our only resolution. Let me know if you have further issues that need resolution. It's all a nightmare in the past at this point, but I may be able to help you fix some of the other details that are related to this if you are more specific.

On another note, we're moving to Odoo instead of Quickbooks. The program has had several major failures since this happened and we're over it. It's taking way too much time away from our business being non-functional during business hours while someone (usually me) works with quickbooks support trying to solve the issues in single user mode and everyone else has to awkwardly explain to every customer that we aren't a functional business for an unknown length of time while we try to fix everything. Hopefully Odoo solves some of that, and some other limitations we're running into in Quickbooks. It looks to be very promising, so fingers crossed it's smooth sailing after the pain of the transition!