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Cisco RV345 Router trying to NAT Static Ip's on a CGNat ISP

Hello all, I've got a problem with a smaller ISP in a remote area.  They recently switched us to fiber, from a cable modem.  The speed of fiber as we all know is insane...750x750 to be exact.  We're coming from 500x15 on cable modem.  The issue that we have is that they use CGNAT, and the requirement is that every device that needs a static ip has to be binded to a mac address.  Now I've already tried the standard static NAT with the router mac address binded to .250 address.  That works like a champ, and speedtests show that I'm getting full speed.  I have an exchange server and a spam filter appliance that I need static ip's for since they are tied to a and, they have to have public statics.  Now when I static NAT them, no traffic is getting in or out, and they go offline from the internet, but obviously can still ping and see all the device's within the network.  Is there a work around, or a different approach to the set up that I'm missing?  Does the router have a separate mac address for maybe each lan port, or maybe for the vlan that I can try to submit, or some sort of mac bridge bypass?  I'm at a loss at this point and ISP isn't much help.

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