Is this perhaps anything to do with the “fill mode” button? - this is above the Exposure toolbox button (on my system). This from Rawpedia -
Processing Profile Selector
The Processing Profiles drop-down list lets you apply bundled or custom processing profiles. See the File Paths article for information on where these processing profiles reside on your system.
Pay attention to the “Processing profile fill mode” button!
“Fill” mode Profile-filled.png
When the button is activated and you open a partial profile, the missing values will be replaced with RawTherapee’s hard-coded default values.
For instance if you apply a partial profile which contains only sharpening settings, all of the remaining tools (such as Exposure, Tone Mapping, Noise Reduction, Resize, etc) will pop into their default positions.
“Preserve” mode Profile-partial.png
If the button is deactivated and you open a partial profile, only those values in the profile will be applied, and the missing ones remain unchanged.
For instance if you apply a partial profile which contains only sharpening settings, only those sharpening settings will be applied, and your other tools remain unchanged.
The state of this button will make no difference if you apply a full profile, but most of the profiles bundled with RawTherapee are partial (for good reason).