I’ve sometimes have this problem but much less frequently than you are getting it. I have it narrowed down, at least in part, to one piece of equipment in my network. I have a Netgear Nighthawk cable modem/router on one side of the house and on the other side of the house I have an ASUS router in Access Point mode connected via ethernet to the Nighthawk. I only get the problem on the Roku connected to the kitchen TV which is connected via WIFI to the ASUS. I swapped the Kitchen TV Roku with a Roku that was connected via WIFI to the Nighthawk. I also swapped the WIFI connections at the same time. Interestingly, the problem stayed on the Kitchen TV, now using a different Roku and now connected to the ASUS. Thus the problem stayed with the ASUS, not the Roku.