Why am I getting two windows in Sketchup?

I’m getting two windows when I go into 3D warehouse. It will not allow me to select the
allow cookies tab, and it switches between the two windows when I’m looking for something
to add into my model from the warehouse. Then it won’t allow me to download the
item I want to add into my model. Can someone help me on trying to fix this bug?

Is your screen set to a bigger scale factor than 150%?

I am experiencing the same problem, the second screen appears on top of the original, smaller and like a blurred image and seems to prevent downloading models from the 3DWH.
I have the same problem trying to download the latest 2021 SU update, it will not download, this has been happening for quite some time, so any help to correct this would be very useful.

Having said all of the above, I checked my screen scale as Anssi suggested, which was set at 125% (Recommended) which I have been using for many years. Once I reduced it to 100%, Presto !! everything is working OK and have finally installed the latest SU update and can access 3DWH again, Thank you Anssi for your help.