Hi, I hope you are well. I'm sorry to read you are having issue with the function Picture-In-Picture. Do you read the [https://support.mozilla.org/en-US/kb/about-picture-picture-firefox relative documentation page]? Maybe you can find some useful tip. If you refer to the Windows preview when you go with the mouse on the taskbar Firefox icon this should be asked on the Windows support forum or to your system operative support.