It normally takes seconds rather than minutes.
It is possible that servers in your uplink chain are behaving poorly rather than those at Nabble itself.
You'll usually find that if it is a Nabble problem they'll be others posting similar complaints in fairly short order - and I don't see that at the moment.
If it is an individual problem at the Nabble end of things then it would be worth posting the URL of your forum so one of the Nabble team can investigate.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.