Makes you wonder if the Roku is searching for ads when it freezes the video because it gets caught in some kind of loop and runs out of memory. I just switched off the Personalize Ads on one of mine and will do the other two shortly. If all 3 stop exhibiting the problem, I'd say we found the fix and with zero help from Roku.
The reason I went with Roku is because of their reputation. A neighbor has been using one since they first came out and it has been 100% reliable. We have a Firestick that we used in our summer place, but it will not let you use the Spectrum app. When I went to see what other brands would work, the people in the various stores all said to get a Roku. I had a Spectrum tech in my house for an issue before I got the Rokus, and he said to get Rokus.
One problem does not flush all the past reliability away. So, we need to see if they will come up with a software update that fixes the problem. I have seen other digital devices (not streaming related) that were robust and worked great when they came out. But when the company came out with a "new and improved" version, both the reliability and durability went downhill. I tend to think that they build the best digital gizmo that they can when they start out, and once it is commercially successful, they put all their effort into removing cost to boost profitability and when you start removing cost, you also tend to remove quality. I'm retired from what was once a corporate tech giant and have seen that process in spades.