Adobe RGB not recognised by PS and Bridge anymore

Thank you! That was indeed it. No idea how that got changed, up until this glitch I hadn't even heard of Rec. 2020. Actually had to Google it... Anway, all's well that ends well 🙂

PS - if it opens as Rec.2020 in Photoshop, it's because you have ACR workflow settings set to open as that. Change that to Adobe RGB or whatever you prefer. Rec.2020 is not something you use for still photographs.

Well, something has changed though.

Bridge, Photoshop and Camera RAW showed the colour profile the camera is set to until recently, Photoshop did not display the dialogue informing me the colour space of the file I'm opening differs from the one it's set to, and so on.

And Photoshop and Camera RAW still show that the files are in Rec. 2020, which isn't untagged either. And, most importantly, if I don't actively assign a different colour space, files are saved with Rec. 2020. None of this happened a month ago.

There's nothing wrong. Raw files will always show as "untagged", because they are.

The camera setting for color space only applies to the camera-processed jpegs/HEIFs.

A raw file has no color space until it is encoded into one in the raw processor. A rendered RGB file has a color space, but not a raw file. That's just a data dump from the camera sensor.