AzireVPN getting WG config fails

I have existing AzireVPN configs in my GL-MT3000. After not using it for a month or two, I tried reconnecting to AzireVPN, but the connection didn’t work.
So I went to update the VPN configs, however both logging in and updating the configs fails with:

-15get azirevpn config failed!

I verified my account is correct and active on AzireVPN. Maybe a change in the API? What can I check?

Pls go to your Azirevpn account dashboard and remove old keys.

Did that… didn’t help unfortunately.
In the meantime I had tried Mulvad and NordVPN, and all of them had issues with the setup.
What finally helped was resetting the GL iNet router to factory setting, and then starting with a fresh setup. Something must have gotten borked in the internal config, not sure.