That's what I meant with "full support" - this new user has no relays in kind:3, and you're not reading from kind:10002 - so which relays are used when they post? Only your relay? Some default ones?
Discussion
I'm not sure how it works, in that case posting just shouldn't work. nostr:npub19f2765hdx8u9lz777w7azed2wsn9mqkf2gvn67mkldx8dnxvggcsmhe9da should know more about how web app works. Maybe it reads relays from the extension if it's setted up there.