NETGEAR Cable Modem CM 700 with an Orbi RBR40 very slow guest network!

I have had this setup for over two years with no issues.  Now with two tenants working from home using the guest network given to them they are experiencing slow unstable speeds when I can get upto & over 275Mbps.  Can I log into my CM 700 modem and adjust speeds so they get more than 20-40 Mbps?