Need help - Host Alert - Info External command error: No Response

Hello - I need help figuring out how to fix my alarm error. This alarm was up/down for a month. It would come back up eventually. We had our ISP go out and switch out router.

AC1200 Wireless Dual Band Router
Model No. Archer C50

I am able to ping the sw1-SATX switch from router and I have also opened up forwarding to this switch using port 5665/5666. This did not fix the issue. The switch is a Extreme Networks X440-24p. I can SSH into switch, but not sure what I should be looking at on switch.

My Incinga version is Version 1.8.4. I am running it on Linux, which is another issue because our Senior Engineer who did our linux support is no longer with the company. I really need some help on troubleshooting this error. The error is below and I would appreciate any help. Thank you so much.

***** Icinga *****
Notification Type: PROBLEM
Host: sw1-SATX
State: DOWN
Address: sw1-SATX
Info: External command error: Timeout: No Response from sw1-SATX:161.