Softphone on cellphone with dynamic IP, how to configure firewall on freepbx Vultr VPS

It’s no problem to register extensions with statics IP, also easy to configure firewall rule.

However when cellphone is using mobile data, it’s IP changes very often. is there any way to let softphone register with VPS server except disable firewall?

Enable responsive:
https://wiki.freepbx.org/display/FPG/Responsive+Firewall

The responsive firewall blocks my dynamic ips from time to time for 24hours.
There are about 3 extensions with a Cisco SPA112 and Panasonic TGP600. They re register in a cricle of 60 seconds.
But i dont know why Responsive Firewall blocks the ip after a few days.