You can enable this function.

Go to Opera Settings and search command+backspace

You will find this shortcut assigned to "remove highlighted expression."

Delete this shortcut and voila, it will work as expected.

I think PiP is a great feature, for example for the Google Meet videos or youtube enabling the translucid function. Great! but, how can I disable the clicks over the floating window?

How can I continue the web navigation if the PiP window catches all the clicks? I need to move it continuously in order to browse or work while I'm watching youtube or at a video conference

I was looking for the same.
I use a lot the PiP feature but i have the same problem. I need to click on the window below of the PiP.

You can enable this function.

Go to Opera Settings and search command+backspace

You will find this shortcut assigned to "remove highlighted expression."

Delete this shortcut and voila, it will work as expected.