Before you preach on CMYK and RGB differences within the light spectrum on displays, stop right now.
Now that's out of the way: InDesign has taken upon itself to signficantly skew the swatch color appearances of CMYK color values unlike before. I'm unsure where or why this happened, but I'm curious as to whether a setting was reset by accident. My main issue is blue coming across purple.
I should also note that swatches within InDesign appear differently than CMYK swatches within my creative cloud library which I use for our brand library. This was not an issue until today. I remember it popping up years ago but can't remember how I remedied the situation.
Proof setup is also grayed out, so that could be tied to the issue. If I open the ink manager within the swatch panel, everything appears correctly.
What are your colour settings in InDesign, and in the other app that shows different colour? Sounds as if the profile may have changed. It's normal (and correct) that CMYK colours change screen appearance if you change CMYK profile.
I actually just fixed it this same way. I had to uninstall and delete all my preferences with InDesign due to a sporadic issue of InDesign loading without my preferences. All I needed to do was reload my color working spaces.
Check your Colour Settings in all your apps, including Bridge. There is a current bug resetting your preferences to unexpected settings.
Search this forum for what to do if that's the case.
Oh lovely. Thanks for the heads up!