USBC peripherals not connecting to new iMac or Macbook Air

Hi all, I am not sure if this has been answered anywhere, but I cannot find it. I have some new 2021 iMac's as well as Macbook Airs in the school I am in, and have noticed that I cannot connect 3rd party USB C devices to them. They physically cannot plug in (no 'click'). One is a SanDisk USB drive I have had for 3ish years, the other a brand new Satechi USBC wired mouse. Funnily enough we also have Satechi USBC to multi adapters that work fine. Has anybody else experienced these issues? I would hate to have to go buy new stuff seen as I have just about used all my budget on these new machines. Thanks in advance.