I have done more factory resets and scan for channels in the past 6 weeks than I have done over the past 2 years.
I have a T6 and came home on tuesday to find a bunch of channels not working. I assumed it was an ecm being tuesday and all, but all my 110/119 and about half of my 129 channels were all working but the other half of the 129 were down. Half of those said "no signal" and the other half were gone from the tvheadend and said "no service assigned to channel".
A factory reset and rescan the channels and it was back to normal.
A few weeks ago I had a similar experience after an ecm I only had a few channels that came back after and I had to rescan, and it was all good.
As a reseller for one of the services, I have had many emails from clients who lost channels on many types of receivers, but were connected to server and they all assumed the server was responsible, and I tell everyone to reset and rescan and they all were up after they took my advice. Most don't tell me they are up again, I have to ask them if everything is good.
The biggest problem is users who don't ask me for feedback or let me know they have problems, and they just run out their subs and don't renew thinking the server is ****ty.
I have seen many complaints in the forums and I told one guy who had been bitching for awhile to reset and rescan and then he says "it is working now" after calling Turbo a scammer.

Why are they doing to the software of our STB's during an ecm?
This is a fairly new thing and if the users are not aware than they just blame the server.