Cliquer sur "x" pour fermer la bannière de bienvenue ne fonctionne pas jusqu'à ce que la page soit rafraîchie

I tried disabling all plugins using safe mode. And also manually disabled all plugins and components. But still won’t close for logged in users.

Browser dev tools shows no errors and status 200.

Any hints on how I can investigate? I also updated Discourse to current. No luck.