Solving playback issues

[Jazmin13]

I have a Roku Streaming Stick 4k which is one year old and an LG TV also one year old. All of a sudden I can no longer connect to Roku. The remote turns the TV on & off and volume works.  All I get on my TV is ROKU which fades in and out- the screen will go black, then “Roku”  comes back on, then screen goes black again. I cannot even get the Roku Home Screen. I have unplugged the Roku unit from the outlet and removed the streaming stick.  I have tried resetting the remote.  I have three other Roku devices (all much older than this unit) and they are all working fine.   When I am watching tv (using the LG apps), “ROKU OTT”is showing in the upper right hand corner.   Everything was working fine until three days ago. 
What do I need to do to fix this?

[renojim]

Try a different USB power adapter from a phone or tablet that can supply at least 1 Amp.

[stevegoldfield]

I have this same problem after updating to the latest version of MacOS. My MacBook Pro says "Unable to connect to Roku Streaming Stick." I'm going to repeat the initial connection steps to see if that resolves the problem.