As a workaround for this issue with your mouse, turn off "Activities Overview Hot Corner" in the "Top Bar" tab of Gnome Tweaks.
This obviously is not a solution, only a workaround. To "really" solve the issue, i.e. continue using the feature without the sensitive triggering, you may need to use smooth surfaces, and eventually tweak the mouse settings, or perhaps even use another mouse.
This setting is off by default in Ubuntu. Turning it on allows to display the activities overview by moving the mouse to the top left corner. That setting is turned off by default in Ubuntu. Apparently your mouse is either very sensitive or defect to the extent that a rough surface inadvertently causes you to trigger the application overview. Also other users sometimes find this feature causes the overview to be triggered too easily. Finally, after 10 years of developpement, Gnome Shell developers will expose the setting to turn it off in the main user interface in the forthcoming Gnome 41.
Turning the setting off will avoid that problem. It is still easy enough to click on the Activities button to display the overview, and that is much less likely to happen inadvertently.
