I don't get Bridge gateway

Hello! I configured my modem in Bridge mode (CLARO Brazil). The RB correctly acquires the valid internet IP but does not acquire a gateway. Because of this he does not surf the internet. If I manually set the IP received by the modem and set the gateway, everything works fine. If I return the modem to router mode, everything also works without changing anything. What can it be?

call your ISP because that might be intentional, when in doubt try to plug your PC in lieu of MT and the behavior should be the same