So fiddled around with it a bit more last night. Removed the hdmi cable from my AVR and plugged into the TV and no still no luck, removed hdmi cables and re-inserted into my devices as I did previously and still no dolby vision displayed on my A8H. I then re-plugged everything back into my AVR as was before since it didn't seem the receiver was causing the issue. So went back to suggestion above by LG8600User to go into the Roku systems settings menu and under display settings I changed it from Auto detect to 4K Dolby Vision tv and voila, the Roku and Sony were playing nice again and DV was again now displaying DV as it had been before. The thing is, I had already set all of this up so long ago it was set it and forget it and never had an issue until now.Did you try the Roku directly connected to the TV yet? Interested to see what the results were.
So probably as some suggested, with all of the software and firmware updates for the multitude of devices in the chain, it seems at times something won't play nice and it causes a chain reaction. I am sure at some point if this happens again in the future then it will only work if I change display type back to auto detect again or something else along those lines
Thanks again to all of you for the help and suggestions to get my issue resolved!