I was watching a meridian flip last night and noticed some odd behavior. Bottom line, it looked like the capture & align modules thought the mount was done slewing for the meridian flip, but the mount was still moving, perhaps had just started moving, and thus the picture taken was full of star trails, and not solvable. Fortunately the align was retried after motion was completed, the alignment picture re-taken, and all worked out. I have logs and screen shots to help, though some details seem missing. Details below.

1) I had many logs enabled, and I have the log file for the evening attached (see the file log_20-30-29.txt). Look at 2019-04-27T00:22:20.58 in the log and note the meridian flip starting about 00:22:20, and the flip should take 5-10 seconds of slewing .
2) You can see my screenshot attached "screen_logging.png" to see what's logging is enabled. Please let me know if I should have had more things enabled.
3) IndiMount.png, shows the output of the Indi Eqmod driver. First note that the times displayed are GMT (all the other logs and screenshots show local time), so 07:22:20 on that page corresponds to 00:22:20 on all other pages. At that time, you can see the mount goto command and the slew starting at 00:22:20. As I said, it has to take several seconds.
4) Capture.png shows the meridian flip starting at 00:22:20, and then at the same second, it says: "Telescope completed the meridian flip", and also, same second it says "Performing post-flip realignment".
5) Align.png. At the top of the page you can see at 00:22:22 "Changing filter to LPR", 00:22:24 "Changing focus", 00:22:25 "Capturing image". This is being done to take the plate solving image (plate solving fails) which is taken while the mount is still slewing.

Sorry, I don't have the star-streaked failed alignment image. 00:22:25 would be too soon to start the capture of the first alignment image if the meridian flip started at 00:22:20, but it did because of the reported/immediate "telescope completed the meridian flip" at 00:22:20.

Please let me know if I can get you more info.
Hy

I watched the meridian flip again tonight, and this night, no issue.
If you look at the text below from the Capture logging on the capture tab, you can see that there's a 50s gap between downloading the last image and completing the meridian flip slew.

2019-04-27T22:11:21 Capturing 240.000-second Green image...
2019-04-27T22:11:18 Post meridian flip calibration completed successfully.
2019-04-27T22:11:04 Performing post flip re-calibration and guiding...
2019-04-27T22:11:04 Post flip re-alignment completed successfully.
2019-04-27T22:09:41 Performing post flip re-alignment...
2019-04-27T22:09:41 Telescope completed the meridian flip.
2019-04-27T22:08:51 Received image 5 out of 8.
2019-04-27T22:04:46 Capturing 240.000-second Green image...
2019-04-27T22:04:45 Received image 4 out of 8.

and looking at the indi control panel for the mount agrees with this timing (again, indi in GMT, capture in local time):

2019-04-28T05:10:09: [INFO] Align Pointset: added point 4 alt = 62.9796 az = 181.9
2019-04-28T05:09:39: [INFO] Telescope slew is complete. Tracking TRACK_SIDEREAL...
2019-04-28T05:09:39: [INFO] Iterative Goto (2): RA diff = 1.15 arcsecs DE diff = 0.05 arcsecs
2019-04-28T05:09:38: [INFO] Iterative goto (1): slew mount to RA increment = 4799, DE increment = 0
2019-04-28T05:09:38: [INFO] Iterative Goto (1): RA diff = 44.89 arcsecs DE diff = 0.05 arcsecs
2019-04-28T05:09:25: [INFO] Align: current point is 3
2019-04-28T05:08:56: [INFO] Align: current point is 0
2019-04-28T05:08:53: [INFO] Slewing to RA: 11:20:51 - DEC: 13:07:57
2019-04-28T05:08:53: [INFO] Slewing mount: RA increment = -4607252, DE increment = 4005547
2019-04-28T05:08:52: [INFO] Setting Eqmod Goto RA=11.2904 DE=11.7667 (target RA=11.3475 DE=13.1324)
2019-04-28T05:08:52: [INFO] Aligned Eqmod Goto RA=11.2904 DE=11.7667 (target RA=11.3475 DE=13.1324)
2019-04-28T05:08:52: [INFO] GOTO ALign Nearest: delta RA = -0.057081, delta DEC = -1.365656
2019-04-28T05:08:52: [INFO] Starting Goto RA=11.3475 DE=13.1324 (current RA=11.2921 DE=11.7666)
2019-04-28T04:20:33: [INFO] Device configuration saved.

Not sure why yesterday was problematic and today was OK.
Some kind of threading issue?

Hy