We have a new Roku Ultra model with an enhanced “point-anywhere” remote. We have been able to sync the remote with the Roku. We have also been able to control our TV with the remote. The issue that the remote repeatedly loses the ability to turn on the TV and Roku. We assume this means the remote loses sync. The issue happens when the Roku and TV are idle for multiple hours, such as overnight. When this happens, we are able to reset the remote to the Roku and TV by following the directions in your help page https://support.roku.com/article/208755708
We power cycle the Roku device and remove/replace the remote batteries to reacquire functionality.
The issue we are having is that the remote does not stay synced. We have had to reset it multiple times to get the functionality back.
Note that the Ultra, as with all Roku devices, does not turn off - it is operational whenever receiving power. Since the Ultra's power supply is hardwired to its cord, the Ultra is plugged into the wall and receiving power.
The remote can only turn on a TV that is still receiving power, i.e. in a standby mode. If it is completely powered down the Roku remote cannot turn it on. Check your TV settings to see if it can be put into a "standby", "quick start", or similar mode.