They could use browser cookies to remember your computer, but most likely use the WiFi MAC address. Many computers allow you to change the MAC address. In Windows, it is under control panel, hardware, device manager, network, wifi adapter preferences, advanced. Some computers have options to select MAC randomization under network or privacy settings. Toggling this from on to off or off to on should result in a different MAC address.

If they use cookies, you could try a different browser, or a private browsing window. It still may not let you but it if you are logged in and they already marked your account as slow internet. You could always complain to the front desk for a freebie or they may even be able to fix the issue.