Something still not right. In fact it seems to get more and more complicated ! HOw on earth did you manage to update the V5, because you need the code number on it to make the change. Have you checked the record ?
You sold the car in June 2021 and say you sent off the V5 for its transfer to the new owner. The bailiff told you the V5 last update was July 2021 indicating some sort of change, yet in June 2023, 2 years later, you apparently crossed the Merseyflow Bridge and didn't pay. The V5 July 2021 update after selling the car in June 2021 indicates that following the sale of the car, the V5 was changed. DVLA send out a letter to the previons owner when they change, so you would have received this, presumably at your previous address.
I suggest you contact the name and address of the buyer of your car to find out what has been going on. Maybe the car was sold on, who knows.
You should also contact DVLA supplying your name and address, and ask them what their records show when you ceased to be the registered keeper. Point out you sold the car in Jund 2021, and to the best of your memory are sure you sent off the V5. YOu will need this information to put on your PE2
As for the bailiffs, if you pay, it does not preclude you from submitting an OOT SD. At the moment, unless you can get the OT accepted, you are responsible for the debt.