The same thing is happening with our remote. It seems the back button is malfunctioning (probably sticking internally). It continued trying to back up all night, so it's not a neighbor playing with us. Batteries have been in and out. It's impossible to watch anything and may require a new remote.
You can also find them locally at many retailers like Walmart and Target.
If you do not have a Roku stick that requires a wifi-direct remote, there are many inexpensive universal infrared (IR) remotes you can purchase locally as well. Just be sure it says it contains codes for Roko devices.
Roku Streaming Stick +, 3810X, Ser YH0059427035, wifi - Samsung UN55ES6100
Roku Streaming Stick, 3600X, Ser 5S56D8240827, wifi - JVC EM37T