I'm trying to access the website www.spea.pt (Portuguese Society for the Study of Birds). When I access the website from Arch Linux (or from my android phone) everything works. However when doing so using Ubuntu (18.04, 20.04, Kubuntu 21.10, or even my Ubuntu touch phone) I always get this error:
Forbidden
You don't have permission to access this resource.
Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.
This occurs regardless of the used browser. Does anyone have any ideas on why this is not working? Is there maybe some block list built into Ubuntu?