My Router was confiscated from my dorm room on the account of it running a rogue DHCP server running on the WAN end

Hello Reddit,

This may not be a technical networking question, but I need some help here. I do have a basic understanding of how computer networks work, but nothing more than that. I will reply to your responses if I don't understand something, so please be patient with me.

Last month, my college campus' IT team confiscated my router which I have been keeping in my dorm room for almost a year, saying that it was running a rogue DHCP server working on the WAN end. The representative explained to me that my router has assigned IP address to other devices trying to connect to the campus network and hence, they have not been able to access the network resources or connect to the internet.

The router runs OpenWRT. I have been using this router for almost a year and there have been no issues. The IT representative told me that they have been monitoring my router and said that the rogue DHCP server has been detected very recently (A week before the confiscation). I have made no changes to the default configuration that OpenWRT comes with when installed.

I have two questions. Firstly, can a Router/Firmware (OpenWRT) malfunction like that suddenly? Is it a heard of issue? And second I know that all switches used in the network are all Cisco switches, and don't they come with DHCP snooping?

They have landed me with a hefty fine and taken other disciplinary actions - they have basically flagged me as someone who has actively tried to disrupt the network.