IIS and OWA 2019 - Excruciatingly slow

Hi all,

I've got a fresh install of IIS/OWA2019 sitting on top of WS2019 acting as a AD controller and SP2019 Single-Farm server (this is a fancy SOHO setting if anything).

Here's a sample session from loading https://mydomain.xyz/owa until it finishes:

https://ibb.co/60sS60S <-- link to the image ( I'm too green to get the image-link right :/ )

As can be seen (hopefully :) ) the logon.aspx with a redirect URL as GET parameters takes 12.1minutes to load!

That's crazy. So of course I wonder, what might be the cause of this? I haven't found anything concrete yet myself - I've tried to disable the CRL lookups for .NET 2.x in IIS, but to no avail.

Any ideas would be most welcome.

Thanks.

   Thor