New problems with my two Roku 3800 Streaming Stick with update to Software Version 10. When pausing a program and the screensaver kicked in, when hitting play to resume, it would exit the app running and randomly start a different app, or even install a new app. It happened with the screensaver starting in all wait times. I had used the Aquatic Life screensaver, then switched to the Cityscape and had the same problem, then went to the digital clock, and it seems to be OK now. I didn't have these problems with the 2 screensavers before the update. Update 198 didn't fix the problem, but fixed the non-functioning volume control on the remote.
Pressing play on a screen saver with ads, does normally go to the advertised channel. As I recall, there's a little icon that indicates that pressing play takes you there - though it's a bit tiny. I switched to clock screen savers years ago to avoid having to think about this;