Image is resized when adjusting borders

Since a few weeks I have the following ‘effect’ in Photoshop.

I’m opening an image and when it’s on screen, I adjust the image borders (I mean the borders of the screen that holds the image) to make that screen with the image smaller. In doing so, the image itself also gets temporarily smaller and afterwards retakes its original size on screen. I’m losing time with this effect and it is also disturbing.

I would like to know how this effect can be switched off.

Adobe Virtual Assistant suggests I should deselect the Resize Windows To Fit option, or that I should deselect the Zoom Resizes Windows option, but this doesn’t work.

So which Photoshop option would control this effect?