Strange issue

I have a strange issue.
I am using a vega 200 gateway(192.168.0.75) for my pri line ,and the FreePbx is on 192.168.0.200.
Until today everything was working fine.
Suddenly i can not ping from FreePbx the Vega and via versa.
I had to change the vega ip to 192.168.0.74 to receive again calls.
It seems that the only ip address the Freepbx cant ping is 192.168.0.75.
Everything else is fine.Just this specific ip address is not accessible.
Any ideas,please
Thank you
EDIT:
I made a firmware update on the vega 200.
In the documentation it states that i should do a factory reset after firmware update.
Will i loose my current configuration if i perform a factory reset ?
Thank you

did something else take that IP
Check your firewall

You mean the firewall on the Freepbx ?There is no firewall enabled on the FreePbx.

Resolved.
The ip (192.168.0.75) was listed in SIP-Fail2ban
reject-with icmp-port-unreachable
After deleting the entry everything is working properly.
Thanks