Multiple Windows Memory Deal Breaker

And the crash signatures you're seeing are from what code path? (Expecting you've ruled out any addons by running in Troubleshoot Mode first etc.)

1. Enter about:crashes in the Firefox address bar and press Enter. A list of Submitted (and Unsubmitted, if any) Crash Reports will appear, similar to the one shown below.
2. Copy the 5 most recent Submitted Report IDs that start with bp- and then go back to your forum question and paste those IDs into the "Post a Reply" box.

Note: If a recent Report ID does not start with bp- click on it to submit the report.

(Please don't take a screenshot of your crashes, just copy and paste the IDs. The below image is just an example of what your Firefox screen should look like.)

More information and further troubleshooting steps can be found in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

Thank you for your prompt reply.

Last 2 Listed Crash Reports: 65067d2f-e916-ea98-dc30-893c2ebbab4c 7a8f86d8-3b89-aeb3-fe2f-3b67580cf83d

These are not uploaded yet — please follow the guide earlier to get them submitted, and once they expose the correct bp–… pattern, share that one. Thanks.

bp-1fe34ec6-1ec4-4318-917f-896c70261007, bp-69db951f-4ba9-4032-8f3f-d2b140261007

Aaah, that's broken pipe from the X11/Wayland display system — Firefox just gets terminated by its closing the connection. Sorry, you might need to look into your windowing system, or video drivers etc. — we don't even see the reason.

You might see something in journalctl around the time of the crash.

If you have widget.wayland.fractional-scale.enabled preference true, you can try setting it false to see if there's any difference.

thank you for your prompt replies. I'm running latest linux not windows. it sounds like the issue is in the OS not firefox.

Yes, since the question did not include the browser troubleshooter data, it was not apparent which windowing system you use on your presumably Ubuntu.

If you can try changing your system settings to not use "fractional scaling" https://itsfoss.com/enable-fractional-scaling-ubuntu/ — i.e. if you use 125% or 150% see if just trying to run with 100% stabilizes things for you.