Hello
Semmy and welcome to the
Kitz forum.
Congratulations for your successful research in finding the origin to those gaps in your bit loading.
Unfortunately (for you) those three broadcasters are licensed to make use of those frequencies whereas we, users of xDSL signals carried on a metallic pathway, have no "rights" / "say" / "privilege" to any of the frequencies that we attempt to use.
The only way that such RFI can be minimised is to ensure that circuit has good AC balance, there are no HR or semi-conducting joints anywhere along its length (which could allow cross-modulation & perturb the differential mode of the CO to CPE circuit), a Mark 2 SSFP is fitted at the NTE5/A and the length of the circuit from the SSFP to the modem/router is kept as short as possible.
Depending upon whether you would be willing to accept the insertion loss, the fitting of a BT80-RF3, just before the NTE5/A, may also help to minimise those signals' ingress.