Quick Connect v 5.5 is not working

Hello,

I have multiple locations when QC 5.5 is still installed and in one location, without any reason, QC stops working.

Error message in the file:

Where are no valid Connection Points now to process link. Service ReplicationGroupId='**************************"

Connectivity with the IAM server works. Port 808 is open and I open telnet and connection is fine.

The connection works for 2 days.

What else should I check?

Ping works,

Telnet works,

a password txt file is created on local DC.