AutoFocus Problem - random position appears

Strange behavior, thoughts welcome.

Running SGP v3.0.1.0 with a Moonlight NightCrawler.

NightCrawler works fine. Filter offsets work fine. Manual autofocus routine works fine. Temperture compensation Wizard works fine. FYI, I autofocus with light pollution filter, and use offsets for NB.

Started a sequence with two Targets, one event each.

AutoFocus routine ran on target 1. No problems.

Slew/Center to Target 2, AutoFocus Routine ran again, determined new focus point. No problems.

Focus point from log file :

[06/04/18 00:07:31.259][DEBUG] [Camera Thread] Auto focus HFR calculated at: 1.85
[06/04/18 00:07:32.263][DEBUG] [Camera Thread] Auto focus is complete (best fit method: 16366; HFR 1.84)…

SGP correctly sets Filter to Ha (and gets offset correct) :

[06/04/18 00:07:37.333][DEBUG] [Sequence Thread] AF is complete, continuing sequence…
[06/04/18 00:07:37.333][DEBUG] [Sequence Thread] EventMarker 4 - t:M17 (1); e:0; f:0; o:
[06/04/18 00:07:37.333][DEBUG] [Sequence Thread] Setting filter position 2…
[06/04/18 00:07:37.339][DEBUG] [Sequence Thread] Setting filter: Ha…
[06/04/18 00:07:37.339][DEBUG] [Sequence Thread] Moving filter wheel, isMoving, check 1…
[06/04/18 00:07:37.339][DEBUG] [Sequence Thread] Moving filter wheel, isMoving, check 1 is complete…
[06/04/18 00:07:37.344][DEBUG] [Sequence Thread] Adjust focuser pos per filter: Moving focsuer to focus position (16063)…
[06/04/18 00:07:37.344][DEBUG] [Sequence Thread] Adjust focuser pos per filter
[06/04/18 00:07:37.344][DEBUG] [Sequence Thread] Old filter: Light Pollution; Focus pos: 16665
[06/04/18 00:07:37.344][DEBUG] [Sequence Thread] New filter: Ha; Focus pos: 16063
[06/04/18 00:07:37.344][DEBUG] [Sequence Thread] Pos delta: -602 steps
[06/04/18 00:07:37.344][DEBUG] [Sequence Thread] New position-> (current: 16366) + (delta: -602) = 15764
[06/04/18 00:07:37.344][DEBUG] [Sequence Thread] Focuser moving to 15764
[06/04/18 00:07:37.392][DEBUG] [Sequence Thread] Focuser move call complete
[06/04/18 00:07:38.409][DEBUG] [Sequence Thread] Focuser position matches requested position (15764), continuing…
[06/04/18 00:07:38.409][DEBUG] [Sequence Thread] focuser move is complete…

1st sub in Target 2 (240 sec exposure) is captured…

[06/04/18 00:11:53.127][DEBUG] [Sequence Thread] SaveFileAscom: Done
[06/04/18 00:11:53.127][DEBUG] [Sequence Thread] =========== Save file took 1697 ms

No problems.

2nd sub in Target 2 (240 sec exposure, same HA filter) begins with a slight temp compensation …

[06/04/18 00:11:53.401][DEBUG] [Sequence Thread] EventMarker 18 - t:M17 (1); e:0; f:0; o:
[06/04/18 00:11:53.408][DEBUG] [Sequence Thread] Temp Compensation: Using focuser temp…
[06/04/18 00:11:53.408][DEBUG] [Sequence Thread] Temperature compensation: Adjusting for -0.1 degrees (end: 18.8; start: 18.9; coefficient: -496) for -46.3 steps…

… but Focuser is told to move up 1,074?

[06/04/18 00:11:53.425][DEBUG] [Focuser Thread] SGM_FOCUSER_MOVE_ABS message received…
[06/04/18 00:11:53.425][DEBUG] [Focuser Thread] Focuser moving to 16838
[06/04/18 00:11:53.460][DEBUG] [Focuser Thread] Focuser move call complete

For the next 8 subs, no filter change, SGP gets the temp compensation and focus position mildly incorrect, but not as big as a jump at the initial 1000.

#3
[06/04/18 00:16:06.446][DEBUG] [Sequence Thread] Temperature compensation: Adjusting for -0.4 degrees (end: 18.5; start: 18.9; coefficient: -496) for -198.4 steps…
[06/04/18 00:16:06.471][DEBUG] [Focuser Thread] Focuser moving to 16686

#4
[06/04/18 00:20:18.054][DEBUG] [Sequence Thread] Temperature compensation: Adjusting for -0.5 degrees (end: 18.4; start: 18.9; coefficient: -496) for -241.4 steps…
[06/04/18 00:20:18.062][DEBUG] [Focuser Thread] Focuser moving to 16643

… and so on.

Why the big jump after the initial AF? It found lowest HFR, changed filter, correctly moved focuser to offset, then mysteriously added 1000?

Brian.