Welcome to the forum!
Unfortunately, I think you are seeing a bug - at least one bug. We already know there are a couple of problems using Inkscape in a dual or multiple monitor setup. But this is the first time I've heard of issues using a tablet with the dual monitor.
It looks like this has been reported a couple of years ago:
https://bugs.launchpad.net/inkscape/+bug/1188211 But please feel free to add a new comment there, at least to report that you still see the problem with your version ( 0.92.3 ?). Add any additional comments you think might be helpful for developers to know about. Especially the part about disabling something seems to fix it (that would seem like a great clue for developers to track down the problem).
We've been seeing more and more reports of people using Inkscape (or wanting to use) in a dual or multiple montior setup. So I hope developers are planning to address this issue soon.