Wlan stick does not connect with Wlan repeater?

Moin, I've bought a Wi-Fi stick for my apartment, because I do not want to lay a LAN cable through the hallway. Now the apartment is so big, that in the middle is a repeater, which offers good WLAN in my room. I use this already with mobile phone and laptop.

With my WLAN stick I was able to connect at first, but the connection always broke off sometime or did not connect automatically after the restart.

My roommate has the same stick and this works fine in the connection with our router. So he is not connected via the repeater but via the router and that works.

Does anyone have any idea where the problem could be?

On the stick or the USB slot

Problem Finding the simple exclusion principle.

If the stick of your roommate works for you. Is it the USB slot