Zopim Messanger icon not showing in Windows Safari browser

Zopim messenger icon is showing in Mac-OS safari browser, but if I check in Windows-OS safari browser , it's not displaying. Kindly provide me the reason and if possible suggest me your solutions.

http://ift.tt/1IJcktq

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This same issue showing in the Zopim Live Chat Software itself.

https://www.zopim.com/