FreePBX slowed down significantly


I use FreePBX 6.12.65, I tried to connect a new device, so I created an extension for this device, but when I configured it I was wrong to enter the secret.
Fail2ban banned the ip it was associated with the device, and FreePBX has slowed down significantly (15 seconds just to take the same line with an internal, outside calls coming from when the originator hangs up).
I tried to disable Fail2ban service, but the problem occured yet, so it isn’t fail2ban the problem.

Can someone help me?