Thanks Bill,. I’ve just switched over now so I’ll see how that goes…
Changing from Seren to the crew has made a big difference but I preferred the layout and functionality of Seren. So would be nice to go back to that… 
You may have already fixed your problem but just in caes.
I had a similar problem a few months ago when i overloaded kodi with PVR/EPG. But i was using in a build too so i guess i was really pushing the limits. Once i stopped using kodi as tv guide for hundred or thousands of channels it went away.
If you are only using one addon it should not be a problem.
The problem can be any where from data throttle or issues withe the source site. It is not seren or kodi.
So just an update on this…
I stopped using Seren and use the Crew now and all image freezing has stopped.
I’ll check with Seren again and see if it still freezes.