I’ve had the same issue, where a settled tab has been added to my monthly budget. With most payments you can choose to exclude from budget summary, but this doesn’t seem to be an option when you click on the payment.
I have found a work around however… I transferred the amount I received from the settled tab into an account with another bank. This removed it from my monthly budget summary. I then set the transaction type to be the same, thus returning the budget for that transaction type to zero. I then sent the money back to my Monzo account, which was added to my account balance but not the monthly budgets tab. Phew!
Obviously would be great to have a ‘exclude from summary’ option instead! Thanks Monzo!