Very common issue. Mac and PC, this can happen easily. Better gold plated cables can help, and powered USB-HDMI adapters that have their own source of power can help. I found Belkin better than insignia cables. Sometimes it is a matter of clearing dust, which really should be left with a service technician for both the monitor and the computer that is authorized for it. They can ensure that the right implement is used that will not damage the fiberglass or circuits on the connection port.
I had a Dell WD19 docking station which i used with a Dell laptop, and it periodically would have the issue. Move the same cables to a Moshi adapter and built-in HDMI of the a Mac, and no issue. Same monitors too.
I suspect it was the Docking Station for me.
Also I have a KVM switch it happened a lot on. For that i think I did not have enough power on that switch to manage two monitors, or the switch was cheap.