Rains have come and seems to be a lot more stable and held for 48 and a bit hours before the last resyncs occured. I'll keep an eye on it if there is a correlation with rain and better stability.
One huge thing happened last sync, G.INP was removed from the upstream only and set to fastpath (Interleave 0). Lost 2Mbit in sync speed dropping from 17 to 15.
I doubt the fastpath will hold up long so I think the 15 will get even lower. Wait and see...
I never did a have a problem with the upstream as it has always been the downstream that has been problematic with ES and CRC errors.
Just happy that it's been stable, though no idea what has made it better as I have changed nothing on my end.