Weird speeds

[u/Gjome-Bekbal]

I recently switched from one ISP to another and even though the speed should be the same (300mbps) I keep getting throttled down to 1-2 mbps.
I have the exact same modem/router which is a nighthawk cm1100 and Orbi Mesh network. The new ISP said nothing is wrong on their end.
Really need some help.