TV can’t get a connection with xfinity cable box

TV and cable box not talking.  

Completed HDMI troubleshooting; no issues.  

Tightened connections. 

Cable box blue light is flashing.  

What I see on TV is a loop:  Cable box starts… I see “Welcome…” I get the spinner… then it starts over.  

SAMSUNG TV then tells me to troubleshoot the connections… 

And the wheels on the bus go round and round.