Meridian Flip Calculation by SGP

In TheSkyX, Mira has a transit time of 18:28. My mount firmware is set to meridian flip at 0, SGP at 1 minute. When the sequence is started, the time to meridian flip in the SGP telescope control panel is shown to be calculated as 19:05. Why would there be a 33 minute difference between the two? Thanks for the help. I am currently testing for meridian flip issues and safety with a Hobym crux 170.