Why am I now getting white balance warnings? – #5 by LateJunction – darktable

This is, most probably, a user-error, but I cannot figure out what I am doing wrong:

Over the last 6 to 8 weeks – before and after the upgrade from 3.8 to 4.0 – I have been finding many of my images throw a red warning, as soon as I open the image in darkroom, about white balance having been applied twice. The fix is, in every case, very simple: change the white balance settings from ‘user modified’ to ‘camera reference’.

What puzzles me about this is how the white balance setting ends up as ‘user modified’ when I was sure that it was set to ‘camera reference’ for all my images in the first place. And, indeed, some of the images now flagged as having a white balance problem did not previously have this problem, but have not been edited at all in the last 12 months (for some of them).

Where should I start looking for settings/options/actions that are causing the white balance to be changed to ‘user modified’ without my realising it?