So, does this problem (behavior) seem to come from Argyll ?
The offset is calculated by Argyll, and applied by it. The check for a (imo) reasonable threshold (15) is done in DisplayCAL, because (some) people kept ignoring the self-calibration message, leaving the instrument on screen, which then lead to totally bogus measurements 🙁
As this offset is meant to counteract black level drift (rise) of the SpyderX, I was very surprised to see negative numbers there. I am unsure if this is a problem though – need to ask Graeme about it (by the way, if you want to do that, go ahead – I’m very short on time lately).
And hey! Other poster with this problem… post a log so we can see what’s in there!
Yes please. For this to be useful, it is actually necessary to enable Argyll diagnostic output, like you did.