Color issue since last update

Dear all,

Recently, I've had a change in my photo renderings in Lightroom Classic that I've been unable to explain or correct.

For a few days now, when I go back to the Development module, the photos I've retouched change to a different colour rendering mode (loss of saturation, loss of contrast), even though nothing has changed (see before/after examples). I've made exports with the same settings on two different dates to compare and I also get the same difference on export, with no change either in Development or in the export settings.
Does anyone have the same problem or any ideas to explore?

Thank you very much.
Thibault