I am watching Sling TV on a Roku stick 3500. It used to work fine but, over the last several months, programs suddenly cut to commercials and jump back several minutes in time. It happens on every channel and often I can’t watch for more than 10 minutes before it occurs, whereupon I have to go the home page and restart the Sling app. Meanwhile, Sling works fine on my iPad.
I'm interpreting this to to say the problem occurs in any channel you try to watch on the Sling channel app on Roku, not on all Roku channel apps.
When problems are confined to a particular channel, Sling in this case, it may be that the channel didn't install properly, that it didn't update correctly, or that the installation has otherwise gotten corrupted. A reinstall may fix the problem, so give it a try. Remove/reinstall procedure:
You are right in how you understand the problem. And thanks for the suggestion but, unfortunately, it has not solved the issue.