Replace the batteries in your remote. Dead batteries are a common cause of remote issues.
Turn off your TCL Roku TV. Unplug the power cable from your TCL Roku TV. Wait for about 5 minutes. Plug the power cable back into your TCL Roku TV. Turn on your TCL Roku TV.
Try re-pairing your remote with the TV. This can often solve connectivity issues.
Make sure the TV settings are not on Standby or Sleep Mode. Turn off these features to resolve issues with unresponsive remote.