I had a bunch of issues with this and thanks to the guy that wrote Mount Wizzard I was able to resolve it. Seems that some piece of software had set my high limit to 85 degrees and the target I was shooting was M33 which traveled right through the zenith. So I had a 10 degree dead zone and when SGP commanded a slew for a plate solve, the mount would not actually move. Then SGP would check side of pier and see that start and finish were the same. Then it would go into end sequence mode and park the mount.
Getting the flip slew and flip guide tolerance set is important as is making sure the number is bigger in SGP flip settings so that when it does send a slew command the mount is already into its flip area of concern.
And double check you are not getting errors regarding high limit being exceeded. If you are, then you need to download mount wizzard 3 and set it back to 90 degrees.