New MacBook pro not detecting older USB hub

Hi all -- for a long time I've been using a M1 Mac mini with a KVM switch, which also serves as a small USB hub. I just got a new M4 MacBook Pro. When I connect the new computer to the switch, it detects the monitors fine but not the USB hub. The hub does not show up in the USB panel of System Information at all. The USB ports on the MacBook Pro work fine when connected directly to my iPhone or to an external hard drive I have. I played around with the "Allow Accessories to Connect" settings, as that seemed to help with problems people were having on this a few months ago, but it did not help me. One thing to note is that the USB ports on the KVM hub are all USB-A, as are some of the devices I'm plugging into it. I have the KVM hub connected to the mini on an A-to-A connection. It shows up in the System Information on the mini as being connected to a "USB 3.0 bus", and the KVM appears below that as a "USB 2.1 Hub." The cable I'm using to connect the KVM hub to the MacBook Pro is an Anker A-to-C cable that's worked fine in other contexts. On the MacBook Pro, all I see in System Information are three "USB 3.1 Bus" connections. Is it possible that this is a backwards compatibility issue?