Responsive Firewall Blocks Known Good remote users

Responsive firewall is consistently blocking known good users with no obvious reason? they have to have their IP removed from connectivity->firewall ->status

In my case the remote phones are softphones (microsip) 

forum thread with multiple reports at 
https://community.freepbx.org/t/responsive-firewall-always-blocks-good-external-users/72052

older threads (from this year and 2018) also here that may contain more logs/ ideas:

https://community.freepbx.org/t/sangoma-firewall-banning-work-from-home-folks-with-sangoma-phones/65812

https://community.freepbx.org/t/responsive-firewall-blocking-authenticated-users/41817/31

 vague feeling it may also be related to fail 2 ban but unsure how to prove this. - some logs from my firewall log in the thread, I can gather more info as necessary, generally happens for two of my users daily.