If this helps someone great, otherwise its just to document how I'm having a better time with Now TV lately. I hope it lasts!
Changes I've made:
Going back to my first point: Perfect video quality for the trial period. My credit card gets charged and suddenly the problems kick in. If Now TV would like me to test if a free account doesn't experience the video quality, I would reluctantly, accept and promise to report back in a couple of years after some serious testing.
TL;DR: Set the display type quality to 720p. Do you even notice a difference in quality? And does this resolve the issue for anyone else? I don't work for Now TV so I can't offer next steps - just give feedback on the forum so they know.
I have all the issues you have, and I have done everything you have done and it is still unwatchable. I dropped down to 720p and managed to watch a whole movie, but later that night while watching Sky Sports news the 1970's VHS image quality returned. Nowtv dont seem to have a technical department/customer adviser, and dont seem to care...
@Now-unwatchableyou could also try a full hard reset on the box https://help.nowtv.com/article/hard-factory-reset-now-tv-box-stick (you'll need to log in again afterwards).
Then unplug your router from the power supply for at least 30 seconds (don't just restart it - disconnect the power and allow any internal capacitors discharge fully). Perhaps overkill but I think it works better and re-establishes a better connection to the ISP.
Its unwachable and I too experience the 144p quality of 70's tv all the time. It is total and utter ######! I suspect this is to encourage more people onto SKY tv with a dish. Terrible service, terrible quality, terrible customer service.