Binds not sticking

Hey guys i have searched but have had no luck. I am running multiple hotspots off my router that are nated some binds stick and some binds dont im not sure why. and cant figure it out my private ip address stays the same but for some reason my public one will not stick to that address or mac address and i need this to work correctly for my AP’s to be monitord and for our electric companys metering system. Any Thoughts? one routerboard is on v5.2 and the other one is on V4.14.