I have a curious issue that has me scratching my head. I upgraded a while back from the 5 position ZWO EFW to the 8 EFW. It has been working flawlessly until... I have two projects ongoing currently and I generally like to stack the lum subs as I progress so I can tell how much more data I need. A couple of days ago I decided to stack and went ahead and did some flats with my flat panel. I had to run the Wizard in SGP to get new exposure times. I noticed that I had a shadow in the lower left corner of the L flats that looks like a shadow as in the wheel not being centered on the L hole. I changed the filters in SGP and took some test shots with all of the other filters (6 of them total not counting the Lum)) and all aligned except the L (#1 position). The issue was not present a few nights ago when working on the project. I do not have a filter in the #1 position (Lum) as I use the IDAS D1 LPS on the front of my camera nose as my Lum (due to shadow issues being caused with the 1.25" AD Lum filter). I ultimately had to remap the Lum to the #8 position of the EFW in SGP which aligns correctly as a work around. I am curious if anyone else has seen this issue (i.e. misaligned position) and to how to fix it once my projects are complete and I can break the thing down. Yes I did try to recalibrate the #1 position. All other EFW position 2-8 align correctly after remapping in SGP. Remapping did nothing to fix the alignment issue of #1.