FCGI: (worker 0) Timeout 150000 ms expired while waiting for FCGI response

hello team 

we are facing an issue with our icewarp web service it shows server too busy each 10 minutes , after restarting web control , everything goes well , and then it shows again , 

checking web logs : 

SYSTEM          [00007FDE867F9700] 16:13:44:495 FCGI: (worker 0) Timeout 150000 ms expired while waiting for FCGI response (Processed = 0, Running=1)
SYSTEM          [00007FDE867F9700] 16:13:44:495 Internal Server Error: in cooperation with cgi/fastcgi, Original request:
                                    POST /webmail/server/webmail.php HTTP/1.1
                                    <iq sid="wm-686cff3ef04f9515998599" type="set"><query xmlns="webmail:iq:private"><resources><cookie_settings><item><im>{'status':'online'}</im></item></cookie_settings></resources></qu

the ressources are fine , we are exploring epos version : with centos 7 as an OS 

 /opt/icewarp/icewarpd.sh

IceWarp Server 14.1.0.13 RHEL7 x64

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