premoves taking 2 seconds off the clock

Please post a screenshot that shows evidence of that. The only game you played today shows many moves taking less than 2 seconds.

Hey notmtwain, thanks for responding, and for going the extra step of checking my games.

The game you posted is a good example.  I should have been more clear, while not every move took 2 seconds you can also see that no move took 0.1 seconds and many are between 1-2 seconds.

I suppose you'll have to take my word for it that nearly every move in the list you showed (with the exception of moves that were countered with a check) were pre-moved.

To be clear, I don't think this is a bug or anything.  I'm assuming its some kind of latency issue, perhaps on my end.

Also see this game: https://www.chess.com/live/game/5880552637

I can't point to a specific instance but I can say two things about this game:

 - On several occasions my clock dropped by ~2 seconds the moment my opponent made their move

 - My opponents clock went to 0 three times before they lost on time.  They did not appear to be premoving

you probably lag. I know when I do lag, it takes more than the 0.1 seconds to remove. However, I've never lagged hard enough to make it -2 seconds.

I'm sure you are right, I am used to occasional lags, but the behavior I am seeing has lasted days.  

I just checked the latency from my phone, via wifi, to a random internet server and had consistent pings of 30ms.

Are there any utilities built into the chess.com app to diagnose connection issues?

things seem to be back to normal for the time being. Premoves are taking a normal amount of time and I'm not loosing time on my opponent's moves.

I've noticed that premoves for me take 4 seconds off my clock

that's a bug 

Or your Internet is slower 

Not a bug but excessive lag.

I proved to myself that this issue was real, and had absolutely nothing to do with the quality of my internet connection or router (as lag issues only occurred with chess.com)

BUUUUT, I did track the issue down to being specific to my phone + my wifi + chess.com

If I use another device on my network, there is no problem.

If I use my phone on another wifi, it works fine.

I settled on always playing on 4g instead of wifi and this seems to be fine.

I lost the will to keep troubleshooting.

Problems can exist on the client device, where other processes can cause the browser to lag and/or cause packet drops and resends. The same is true for additional traffic on your local networks segment; I get lag when videos are being watched while I'm on site.

Finally, there can be issues anywhere from  your ISP all the way to the chess.com servers. There are some thing that can be done on the client end to minimize issues.

https://support.chess.com/article/213-how-do-i-fix-my-disconnect-lag-issues

That said, on a mobile device with both wifi and data connections, the device itself may switch between networks, which can cause excessive data packet loss. In that case, only one data connection should be active at a time to eliminate network switching as a cause of issues.

I think your last comment is a good one, although I've never been able to reproduce the issue on another wifi network (using the same device).  I think I've been able to rule out most of your other suggestions (well, within some margin of error given that while the issue will be pretty consistent between games over the course of a few days, I can't conclusively say that the issue didn't clear itself up during a test).

Another interesting this is that if I play on 4G I never have this issue.  BUUUT occasionally my connection drops momentarily, and this will be seen on the latency/signal meter in the corner of the app.

This make's me think that the issue is a momentary dropped connection (or switched network), but maybe the app isn't detecting it when on this wifi (and perhaps that's a quirk of natting on this device).  Which would point to your last comment as being part of the problem.

I'm curious to know if @Byron006 has any more details about his issue.