xdg-activation-1 protocol doesn't work in Sway

So, I found out recently that Firefox added xdg-activation-1 protocol support some time ago and decided to check it out. I use Sway as a Wayland compositor and I tried activating Firefox by clicking on a link in terminal and by activating a notification. In both cases I get the same error message in logs: ''[Parent 30362: Main Thread]: D/Widget [7fd433271800]: nsWindow::SetFocus Raise 1 [Parent 30362: Main Thread]: D/Widget [7fd433271800]: gFocusWindow [0] [Parent 30362: Main Thread]: D/Widget [7fd433271800]: mContainer [7fd4475ac4d0] [Parent 30362: Main Thread]: D/Widget [7fd433271800]: Toplevel widget [7fd44758a660] [Parent 30362: Main Thread]: D/Widget [7fd433271800]: nsWindow::SetUrgencyHint widget 7fd44758a660 [Parent 30362: Main Thread]: D/Widget [7fd433271800]: requesting toplevel activation [7fd433271800] [Parent 30362: Main Thread]: D/Widget nsWindow::RequestFocusWaylandWindow(7fd433271800) gFocusWindow 0 [Parent 30362: Main Thread]: D/Widget missing gFocusWindow, quit.'' What can be causing it? I know for certain that XDG activation works in Sway, because my terminal (foot) activates without any problems (whenever BEL code is received, for example). If that's helpful, I tried both Firefox 97 and latest Nightly - no difference. Steps to reproduce: 1. In Sway, launch Firefox with `firefox --MOZ_LOG=Widget:4` 2. In another program, click on a link, or use https://www.bennish.net/web-notifications.html to send yourself a notification you can click on. 3. Observe an error that I provided earlier in logs.