Sorry, Ray, when I say it was because of the model name, I meant it was because I renamed the model and the model name APCC was expecting was not present.
It's easily re-creatable for me. Last night I was imaging with the model, and shut down normally. To recreate this morning, before starting APCC I renamed the model to a new name.
For simplicity I started just APCC, no ASCOM, no NINA. It auto-connected and and the model "loaded" all zeros (first two screen shots)
I hand-keyed in the goto pane the uncorrected coordinates from the log you have (2d1m7.10s, 85d12m39.2s) and hit Goto.
It took off counterclockwise again (I think I said clockwise somewhere, sorry). I stopped it after about 100 degrees or so, you can see in the 3D where I stopped it. Notice also the custom rate; at this point if I go to the tracking correction status it shows -18000.00 sec/hour. The log shows the corrected slew of +511*15:55.2 again.
At that point (having stopped the slew, but nothing else, no restart) I went to Model, loaded the (now) proper name, and immediately the numbers all changed to something sensible. Without changing it I hit the goto button again and it properly slewed back to where it should be.
It really seems like it is just as simple as removing a model from where APCC expects it to be when it starts up causes this, no special situation that I can see. I must be the only one that likes meaningful names. :)
Obviously I won't be doing that any more.
Thanks for looking at it.