I do think the problem is the Roku app and how it's updated.
The workaround I discovered is to plug all accessories directly into the soundbar and not the smart TV. Apparently, the Roku app no longer likes to see other devices connected to the TV in which it resides.
Remove all HDMI cables except the soundbar from the back of the TV. Plug those instead into the soundbar and reboot everything. My soundbar, TV, and the other connected devices are working like normal.