The focus was suddenly bad after the first two images in the sequence. AF was run at the start and the focus was good for the first two images. One was Ha and the other was OIII. The SGP log shows no other AF was run but the computed focuser position was different for next image collection at 02:17. I had gone to bed after the first two images looked good.
This sequence cycled between the two filters: Ha, and OIII. The SGP log shows the “Old filter” equal to “Lum” at 02:16:44.9. It should have been “Ha”. I think that is what caused the incorrect focuser position calculation.
Aprox time of issue: 02:17
Link to Logs
OS: Microsoft Windows 10 Pro