TL;DR: To disable the automatic movement of the map, set disableAutoPan to true in the properties on infoWindowOptions. See the documentation.
The automatic movement of the map, called auto-panning, can be very useful in some situations. It’s good to make sure people can see all the content of an info window without having to scroll the map themselves.
My Tech Comm on a Map project suffered from that problem, until I disabled auto panning:
The full code is on GitHub.