I get the error if I try dragging the icon to the home screen. But it works if I click "add to home screen" so it auto-places, then move the icon afterward.

I've got a bunch of web pages on my Lawnchair home screen.

Did you mean tabs (to the drawer)? You totally can add new pages to the home – try moving an icon beyond the screen border.

No I mean that if in Brave I say "add this page to the home", the launcher gives an error

Ah, pages like in webpages. Gotcha.

It’s interesting, Lawnchair works totally fine with these “app action” 1×1 widgets, and Firefox can add website shortcuts without any problem for me. I’ll try it in Brave a bit later.

That's strange, that hasn't happened to me. Maybe a reinstall might fix the problem? I use it on a Pixel 8A

Uh interesting. I'm on Pixel 8A too. Could be! I'll give it another shot