A warm welcome here in the Roku Community, FranklinJ!
We appreciate you letting us know about your concern with the left arrow button on your Roku remote and we're here to find you the best resolution possible.
Before we proceed, may we know if this happens during playback (specify the channel) or even when you are navigating to your Home screen? Also, is this the remote that comes with your Roku Ultra streaming player?
In the meantime, you can press and hold the Back and Home buttons simultaneously for about 30 seconds to reset your remote. After doing so, re-pair it again.
Best regards,
Carly