I sincerely doubt you were in contact with Roku support. All Roku support starts at https://support.roku.com/contactus and they make it very difficult to actually reach a human.
Note that the power button on the remote is strictly for the TV. Your Roku device doesn't turn off. After the TV comes on, try pressing the Home button on the Roku remote a few times. It may be in "power saving" mode (assuming the Ultra LT has that mode).
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