I Get logged out from Winbox and lose connection whenever I try to browse websites or download things

Hello.

What do you mean by “lose connection”? Only to your router via Winbox or the whole internet?
Maybe Mikrotik logs something at that time which could be usefull?
EDIT: And “where are you”? Directly connected to ether1 or there’s a switch there and you are “behind” that switch?