Incorrect clock values displayed

[Naviary2]

I noticed from Samet's stream and Sanoy's stream that the clock value of the player whos turn it is NOT is incorrect. What I observed:

A time control with 6 second increment was used. In Samet's stream, after a player makes a move, their clock would go up by 8 seconds, then after the other player moved, it would instantly drop by 2 seconds, for a total of 6 seconds of increment. In Sanoy's stream on the other hand, after moving, your clock would go up by 3 seconds, then after the other player moved it would instantly go up by another 3 seconds, also totaling 6 seconds of increment.

This is very odd. My first guess was that it's related to ping or time zone. But it doesn't make sense that Sanoy's clock would go up less than it needed to and Samet's would go up more than it needed to..

The clock values are updated inside clock.edit()

Sanoy's time zone is UTC+2 and Samet's is UTC-4. I have no issues where I am at UTC-6, but I am also as close as one could get to the server.

Questions to ask:

• Do all players in the same time zone have the same amount of clock incorrect-ness?
• Is it directly correlated with ping? From my observation both of them had very fast ping (<200ms)
• Could it be the player's time whos turn it IS which is incorrect, instead of the player's time whos turn it is not? This would be supported by the fact that Sanoy's clock went up 3 less than it needed to and Samet's went up 2 more than it needed. How can the issue be ping if one number is negative?