I'm going to give Mountain Duck a look. I do wonder what
@brsilb was using.
But, I don't think they would ever prioritize graph.microsoft.com. But there's a chance they would deprioritize it's usage accessing OneDrive over its own native usage. But, it's a stretch. Also, the performance is so bad that there's got to be something else going on.
I might try disabling IPv6 on my network temporarily and try with IPv4. Comcast had some issues the other day that disabled my IPv6 for a short while. Perhaps there are some lingering IPv6 issues at my place.