Update to original post;
Problem disappeared. Originally started over a month ago--episodes would not load. I had not changed any configurations. Using an ultra that has been installed since 2019. ALL other channels would work ok.
Other info:Internet service provider was cable , but I changed to a wireless provider about a year ago; all was working. I changed to a wireless provider as they had a good price. I changed back to my original internet service provider (cable) this week because the price for the same 100mbs was $25/mo vs the $50/mo from the wireless provider. Plus, the wireless provider was going to start charging me an additional $5/mo to autopay via my ccard.
NOTE: I did not change because of the roku issue.
Back to the roku channel issue: I tried everything I could find to resolve the issue, as many of you have also done. Nothing made any difference.
BUT, now I can stream episodes on the roku channel having reverted back to my cable service provider. Who only knows--the shadow knows. I can only guess there is something in the internet transmission protocols that affect roku but not the other channels.
I cannot recommend you change your service provider. My hope is that "ROKU" looks into this issue.