Like others on thread have mentioned, I haven't reproduced this either and I use tmux/vim every day for hours.
I have no doubt you are having this problem, but it is probably one of those unfortunate situations where it is specific to your configuration.
Have you tried using a vanilla .tmux.config?
What version of `tmux` are you using?
* You may know, but in v2.1 the configuration of the mouse changed and there were some problems people had with mouse issues/configuration for a little bit... OOTB,
* Is it possible you're ssh'ing into a machine that is using a version before v2.1 or <= 2.3? (I had problems with the mouse interactions on some terminals with tmux v2.3 that is distributed with current Debian stable release. So I always build tmux from src...
https://github.com/tmux/tmux. It's a wild guess... but I wonder if you are experiencing issues that are quirks in the version of tmux you are using that have been resolved in more recent versions? (even if you don't use Debian... you may be using an older version of tmux). Try `tmux -V`. If you build from src you'll see something like `tmux master` as the version... But if you are using Debian stable, you'll see something like `tmux 2.3`)
Given others can't reproduce your problem and tmux/vim are popular... there is a strong probability that it has something to do with the machine you are ssh'ing into... and/or your .tmux.conf. Getting the latest version of Tmux (which has resolved many quirky mouse issues after changing in v2.1...) and a vanilla .tmux.conf would a good next step. Then start adding options back in. It could be challenging... but its a necessary step to get to the root cause when no one else has repeated your experience.
Pinging on this thread will likely not help until you are able to provide more info... or someone else can reproduce it and provide more insight to help find the root cause.