Tvheadend

I'm using openelec with HTS Tvheadend 3.4.27~gfbda802 and have an issue which i've had for a long time now with tvheadend. It just suddenly looses signal with BBC One HD and BBC Two HD on freesat. I'm experiencing this issue with a dvbsky s952 and experienced it with tbs 6984 and 6985 cards. I changed motherboard during this and just seems to be tvheadend that is at fault. Its not a signal issue as the channel works fine until tvheadend suddenly states there is no signal a while into watching the channel. And its not a tuner issue as the same tuner that lost signal can then be used to watch/record another channel. Its only the BBC HD channels where this seems to happen (tried BBC Scotland HD and had same issue).