How to fix Image upload explorer window problem

Hello,

When I want to upload an image file to Facebook or WhatsApp, the explorer window opens full- screen [on centre monitor of three] covering the whole chrome window.  

I cannot either move or re-size it, but I can alter the 'view' setting.

It changed in the last few days - It used  to open the explorer window on the left screen in a middle-sized window that I could move around or re-size as I required.

To my knowledge, I've not made any changes to settings in chrome.

Both sites work normally in Firefox.

Can anyone help me to resolve this please?

William

Windows / Chrome 108.0.0.0