@ryel 

 

The screenshot you provided show Rx bad packets, therefore the bad packets are incoming to the switch from the modem, in theory anyways!

 

Have you tried moving it to a different port?  port 6 looks free and see if that still throws the same error?   has the modem multiple ports also?

 

Just from experience this is usually caused by cabling, would 100% recommend changing the cable between them (or at least running a tester over it)

 

Hello, Thank you for your response. Anyway, tried changing the cable as well as using a different port, but still the same. Though, when I tried connecting my laptop or PS4 directly to the modem. It works flawlessly. Please advise. Thanks!

You can try logging into the web interface of the switch and setting it for 1000mbps rather than auto

 

This would basically force the connection online, see how that works for you.   Ideally do the same at the modem if this is possible, I'm guesses your ISP is a router rather than a modem?

 

Hello, I tried but failed = ( My remedy, for now, is to connect directly the two AP's to the modem/router. And it is working fine as we speak. By the way, no options to adjust the speed of every-port of the modem/router. Any suggestions for the switch to work again? Thanks a lot!