milk chocolate oil II
If you think about it, running the engine doesn't aireate the oil.
The only thing that turns oil to milk chocolate is moisture!
I would spend the time and money to change the oil and the filter, prime it again, and if you have the same problem, you have a problem.
Think positive, might just have been something in the oil passages and you have flushed it out. New oil might be all you need.
Good luck!