Many ISP's latch onto the first MAC address and the effect is as you posted. Some ISPs need to be called to let your next device use the connection.
The way you wrote this, you didn't use the Sonicwall router after the move.
We recently moved to a new office in the same building just 1 floor up. I disconnected our sonicwall TZ 205 router, HPJG348A switch port. Withing 30 minutes I reconnected it in the new office under the same Internet provider. Connected the computers to the switch port and the network file sharing works perfectly. BUT all 5 computers on the network do not have internet! When I connect the computer directly to the modem or router Internet works. Can someone please help!?

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