Update:
The node was originally running with public IP 203.99.60.213 which stopped working on 19th May till date. Today after discussion with ISP Core team, I got a test IP 58.65.173.10 and 210.2.163.185.
with 203.99.60.213 as public IP, no registration
with 210.2.163.185 as public IP of the node, the problem remains the same
with 58.65.173.10 and wollah , everything came back to life. these IP’s are all allocated to us form our ISP and no blocking is done from their end.
repeater*CLI> iax2 show registry
Host dnsmgr Username Perceived Refresh State
178.32.160.82:4569 Y 50249 58.65.173.10:4569 60 Registered
this reminds me of an old thread on app_rpt-users@lists.allstarlink.org date:Jun 18, 2018, 2:43 PM between Bryan Fields and myself “AP2CJ Node 48092 no longer in DB” https://community.allstarlink.org/t/ap2cj-node-48092-no-longer-in-db/14317/4 in which the resolution at the end was "I allowed your ISP’s entire block and it’s working now in the stats server 
" from Bryan.
Would much appreciate on allowance of IP subnets of Pakistan to be permanent. my node 48092 AP2CJ is also reporting
root@VMASL:~# cat /home/stats.txt
Error! Not Authorized from IP …
73’s