Hello everyone, I’m experiencing ongoing problems with Firefox and hope to get some help or clarification here. Main issue: I’m unable to sign in to my Outlook / Microsoft email account using Firefox. The login page does not load correctly, or the sign-in simply fails (Error 400). When I use another browser (for example Microsoft Edge), the login works without any issues. System information: Operating System: Windows 10 IoT Enterprise 2021 (LTSC, supported until 2032) Firefox version: 147.0.3 (64-Bit) Additional problems: Besides the Outlook login issue, Firefox has recently become more problematic during normal daily use: Text selection with the mouse often does not work correctly Clicking and dragging to highlight text is unreliable or stops working Pages sometimes feel unresponsive, (ChatGPT) Overall, the browser feels less stable than older Versions on Windows 10 22H2 These issues seem to be getting more frequent over time and occur on multiple websites, not just Outlook. I switched my system to Windows 10 IoT Enterprise 2021 (LTSC, supported until 2032) in the hope of improved performance and stability. What I have already tried: Clearing cache and cookies Disabling all add-ons/extensions Testing in Private Browsing mode Restarting Firefox Unfortunately, none of these steps resolved the problems permanently. My questions: Is Firefox fully supported on Windows 10 IoT Enterprise 2021 / LTSC for the long term (until 2032)? Are there known issues with Microsoft / Outlook sign-in specifically in Firefox? Are there known stability issues (text selection, mouse interaction, page responsiveness) in recent Firefox versions? What settings or troubleshooting steps are recommended to improve stability? Thank you very much for your time and support. Best regards, Marco Klecker