I was able to pull apart the way system works and found the issue to be caused by configuration conflict. Keep alive 7 - process responsible for fill of calls was also running on archive server(sight).
Basically calls fill was processed twice, which caused more calls to be added to QUEUE than necessary, Simple thing but never expected for this process to hide on the archive server, which I never bothered to check, until i saw it was the culprit.
If you are someone who ran in to similar issue - ssh in to your machine and open /etc/astguiclient.conf look for line VARactive_keepalives => 1234567etc make sure only one server on the cluster runs process 7
And dont forget to check your archive server as well
Update after watching it for some time, I still see small number of calls cumulating overtime so I will look further in to how balancing is done and post if I find anything. If you have a cluster with dialer only server attached run this SQL query to see fi you are accumulating these calls
SELECT `user`, count(*) FROM `vicidial_hopper` WHERE `status`='QUEUE' GROUP BY `user`
Update- Fully resolves after cluster reboot.