I tried to do just that prior to reaching out to you. I do this and I get the message "This transaction has been deposited. If you want to change or delete it, you must edit the deposit it appears on and remove it first.". The item I was trying to delete was $933.71 partial payment for an invoice.
In the original bank feed, I believe that this payment was part of a larger sum of $13,743.98. Some of these funds were allocated to one invoice in the amount of $933.71. Am I getting this conflict because this $933.71 is connected to a large sum of money? The remaining amount of money of $13,743.98 was allocated to other entries that included invoices and sales receipts.