Channels disappeared

Not specifically Channels related, but I am having a problem in the past week where several of my channels in the UK have stopped working including e.g. BBC Four HD and CBeebies HD. Those channels suddenly started coming up with a ‘weak signal’ message having worked happily before. I re-tuned one of my two HDHR Connects and it now doesn’t see those channels at all, going down to around 139 channels instead of >200 before.

I found this information online about changes to Freeview (https://www.a516digital.com/2017/11/freeview-frequency-changes-where-and.html) which appears to coincide pretty well with when the problems started (I am on Crystal Palace transmitter). I’ve checked the aerial and the antenna and both are fine. Plus all the other channels are fine and have a good signal.

Does anyone have any ideas on how I can fix this? Several re-tunes at different times of day over the last 3-4 days have produced the same results.

Thanks!
Jon

EDIT: Also checking my postcode here (https://www.freeview.co.uk/tvchanges) brings up a message saying changes were made on 21st March 2018 and I need to retune to retain access to a list of services which exactly corresponds to the list of channels I am now missing. But several re-tunes have made no difference and they still don’t appear in the list.

Hi Jon,
I’m in the UK up north in Chester, with a background in broadcast engineering & an awareness of the 700MHz clearance - but not the detail. Is it possible the ‘missing’ TV channels are in a multiplex(es) that fall outside the bandwidth of your antenna? I must stress that I haven’t tried to look at the detail of which multiplexes / TV channels have moved from which channel frequency to another in your area but I would certainly start there. I haven’t bought an HDHR box yet but am planning to and think I read that they do require a decent signal strength from the antenna so it’s possible there was a multiplex(es) on the edge.
Rgds, Steve