Can my PC fry my modem?

[Cudweiser]

I recently built a high-end gaming PC. I plugged it into a Bandluxe LTE modem and my PC did not recognize an ethernet connection. I had my ISP come out, and they told me I had a bad LAN port on my modem. They replaced the modem, and the internet started working. The next day however, I lost my internet connection and now I am getting a message along the lines of "connection doesn't have a valid ip configuration." I've tried several solutions I found online, but none fixed my problem. I contacted my ISP two days ago, and I have talked to 3 of their IT professionals, and now they are telling me that my PC is frying the LAN port on their modem/router. Is this possible?

 

[jsmithepa]

If this is a direct connection, no in-between router, no switches, then indeed it seems your PC is doing something bad.