This looks a lot like the issues I had with my CEM60EC.  The issue had been that after the dither two threads were trying to do guide exposures, terminating each other fast.  So the guide cycle had changed (in my case) from ~5s to 1.8s - and the EC mount doesn't like that, and started doing insane moves.  See this post and follow-ups.
However, Jasem had fixed that in a commit 3 weeks ago, so I'd expect that is taken care of....  Still it might be worth checking the logfile for exposure aborts...

 

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