White background turns sometimes turns grey when saving as jpg

[claudel84161621]

For the last couple of months I'm experiencing this issue where I save a photo with 100% white background to jpg and sometimes it turns grey. Does somebody know if this is a bug or if my settings are not correct?

Today I saved 3 copies of the same file only with some adjustment layer changes and 2 of them have the grey background and 1 does not.

Currently on version 22.4.2 but the issue has been present for quite some time.

[c.pfaffenbichler]

Where are the screenshots? 

Please post one of the original images and the affected jpgs. 

What is the images’ Color Space? 

How do you create the jpg (Save a Copy, Save for Web, …)?