Bug 433609

SUMMARY

When you have multiple tabs open on different pages, media playing in one tab can make the system sluggish and unresponsive, to the point it becomes unusable and forces a hard reboot.

STEPS TO REPRODUCE
1. Open multiple tabs
2. Play video in one of the tabs

OBSERVED RESULT

Video freezes, sound skips or repeats, desktop becomes sluggish and unresponsive. Quickly jumping to a terminal and killing Firefox, allows the system to gradually come back to normal.

If you do not manage to get to a terminal, the whole system will freeze and the only option is to power switch to power down.

EXPECTED RESULT

None of the above.

SOFTWARE/OS VERSIONS

Operating System: Manjaro Linux
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2
Kernel Version: 5.10.15-1-MANJARO
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-6700HQ CPU @ 2.60GHz
Memory: 11,6 GiB of RAM
Graphics Processor: Mesa Intel® HD Graphics 530

ADDITIONAL INFORMATION

To be fair, I do have a lot of tabs open (over 400) spread over 12 different containers, but, with the Plasma desktop add-on disabled in Firefox, the problem has disappeared.