@Rose-A If you add one more step in "manually adding part" of your original post so that initial Invoice Payment is deposited to 12000 Undeposited Funds account all will work.

Receive Payment

...

Select the invoice

Select "12000 Undeposited Funds under" Deposit To

Hit Save and close

This way Bank deposit will work.

Hope this will help someone going forward...

Thanks,

R