Streaming Stick 4k needs to reset constantly.

I purchased 4 Streaming Sticks 4K a few weeks ago.  They worked perfectly until we had a power outage 3 days ago, but my generator started within 30 seconds.  Since then, when I turn all of the TVs using my Roku remotes, when I push my home or any other button the Roku devices don’t start no Home Screen - TV indicates No Signal).  I have to to unplug, then plug each one back in after a few seconds to activate them.  After turning off the TVs for awhile, when I go back to watch them, I have to go through the same process.  Why is this happening and is there a solution?  I’ve tried many things.