Something is up with the front USB 3 ports on the SEi11. When I plug my wireless mouse into one of them it lags and is not useable. I had to do what another user recommended and purchase a USBC to USB expander and plug the wireless mouse dongle into that for it to not lag.
I have the same problem with my unit. Eventually nothing will detect on them and the unit will start to have other failures. It's a sign the motherboard is starting to fail which is common with these units.