The tv volume and power controls on a Roku remote work by direct line of sight infrared (IR) signals. There is no pairing, per se, but only finding the right code set to work with your particular tv.
One possibility is that your computer and your TV use the same code set. Can you place something in front of the computer's IR receiver to block the signal and see if that prevents the problem?
Roku Community Streaming Expert
I am not a Roku employee, only a user like you.
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X | Streaming Stick 3600
If this post solves your problem please help others find this answer by clicking "Accept as Solution.". Please only do this if it ACTUALLY solves your problem.