Marc don’t get too hung up about aerials yet, Is worth noting digital aerials have built in noise filters and have to decode the signal first, however its still possible your older analog aerials will still work but, don’t pull your hair out if it doesn’t
A decent 4g filter or low pass filter is going to be easier than swopping aerials for the sake of a fiver and an outlet plate.
As for thinking about freesat, you wold need new freesat boxes and a dish etc. It would be cheaper getting an aerial guy in lol.
Did you remove your now TV box out of the circuit when testing?
As well as other problems my daughter is Autistic with ocd tendancies, so I know where your coming from 🙂