Yes, that will absolutely cause issues. Even a small cut in the outer sheath can cause issues, the connector needs cut off and re-crimped. Takes about 2 minutes with the proper tools, which can all be bought at Lowes or HD or get a tech out to fix it.
I would look at what internet options are available. I would recommend doing this before finalizing any paperwork. I’ve had too many businesses get everything ready and not take into account the lack of internet until later and most businesses rely heavily on reliable internet these days.
It’s best sometimes to just reset them through the controller and leave them behind. Buy new at the new place.
If the router has 1 gbps ethernet port, the max it will provide is about 940mbps. It’s the PHY limit of a 1gbps NIC.
If you are asking that question here….