The problem with ASTAP is that it is stuck in a 4x4 bin. I have reinstalled it, I have updated everything, doesn't work with my ZWO camera for god knows why, I have done almost every suggestion from the discord server and here, nothing worked. I'm using an older version of the ZWO 1600MM Cool (before the Pro), so maybe that's why.
An uncooled 1600 should work well with ASTAP. Binning is dictated by Nina. If even Astromery.net is failing sometimes, there should be something wrong with the settings.
Binning is defined in Nina at:
The left one "2" is for the image taken. The 0 at the ASTAP setting is auto. So if an image is too large ASTAP will bin again. Using this setting, for an ASI1600 the image will be then binned at 2x2 equals 2328 x1760 pixels.
The I would inspect the image used for solving. You can find the image to solve at:
This FITS you could open in ASTAP and look to statusbar for the pixel dimensions
If the image looks good and has at least 30 stars visible, you could try to press the solve button in ASTAP. If it fails (most likely) you could try FOV=auto option and try all FOV:
ASTAP stack menu, (ctrl+A), tab "alignment". Select auto and press solve button:
If that doesn't work upload the image in %LOCALAPPDATA%\nina\platesolver to nova.astrometry.net and give me the link to the result so I can have a look.