Arch Linux

Description:
When going to youtube, the keyboard input is broken such that any attempt to type text into a search box triggers keyboard shortcuts instead of actually entering key presses. For example, the space key is broken and pressing the letter "i" jumps to picture-in-picture, pressing "f" toggles full-screen, etc.

Other websites are fine and I'm typing this bug report using the affected browser without any issues.

Note: This started suddenly today (10-Mar-2021) after a set of package updates that did NOT include a new version of firefox. I have a list of all packages that were installed today reproduced below to help identify the bug.


Additional info:
firefox 86.0-2

gtk3 1:3.24.26-1

kernel: 5.11.5.arch1-1

Environment: KDE Plasma 5.21.2 on Wayland. Note: Native wayland firefox AND Xwayland firefox exhibit the exact same bug.

Packages recently installed:
2021-03-10 07:42:04 alsa-card-profiles
2021-03-10 07:42:04 appstream
2021-03-10 07:42:04 appstream-qt
2021-03-10 07:42:04 bison
2021-03-10 07:42:04 btrfs-progs
2021-03-10 07:42:04 cryptsetup
2021-03-10 07:42:04 dialog
2021-03-10 07:42:04 ffmpeg
2021-03-10 07:42:04 git
2021-03-10 07:42:04 imagemagick
2021-03-10 07:42:04 iso-codes
2021-03-10 07:42:04 kimageformats
2021-03-10 07:42:04 liblouis
2021-03-10 07:42:04 libnghttp2
2021-03-10 07:42:04 sysfsutils
2021-03-10 07:42:05 libreoffice-fresh
2021-03-10 07:42:06 linux
2021-03-10 07:42:06 pipewire
2021-03-10 07:42:06 python-dnspython
2021-03-10 07:42:06 python-markdown
2021-03-10 07:42:06 python-setuptools
2021-03-10 07:42:06 qpdf
2021-03-10 07:42:06 qt5-webengine
2021-03-10 07:42:07 smbclient
2021-03-10 07:42:07 youtube-dl


Steps to reproduce:

1. Start firefox
2. Go to youtube.
3. Try to use the keyboard in a text input box.