EDIT: @thomasp who is a sysadmin at Vivaldi has mentioned that this can be turned off in the Vivadi settings. See https://social.vivaldi.net/@thomasp/112758811705372022 for details.
@simon I can confirm this also works on @Vivaldi.
Vivaldi staff, is this the best place to report this to hopefully be fixed? Or is there a better place to do so?
@alh @simon @Vivaldi Also checked on my macos vivaldi and then saw this reply. Very curious. :/