Streaming stick keeps restarting

My Roku streaming stick has recently gotten stuck in an endless restart loop before it even reaches the menu screen. I have seen posts on here saying it's a power issue, so even though it used to work fine just plugged into USB power from the TV, I have tried switching to external battery packs and tried plugging it into a power strip. The battery pack only gets the same results as the TV, and the power strip (which requires a cable extender bc the one provided is not nearly long enough) shows a "low power" screen with a link to a Roku website page that will not load. I have to assume that the TV is giving enough power since it doesn't cause the "low power" screen, so why am I still experiencing this reboot loop? I can't even get into the menu to change settings or do a factory reset.