Using the eyedropper in Brush mode does not add colour to foreground. Help!

When using the brush to paint in Photoshop, I would hold the alt key to shortcut the eyedropper to collect the colour I want from a reference image on the page I am working on. Then using the colour I eyedropped continue painting. All of a sudden the alt shortcut while in brush mode adds the colour picked as the background colour not the foreground colour I want to use as paint. This is massively disruptive to painting.

I can't seem to find an option to change this.

To be clear: I want the eyedropper shortcut while in the brush mode to collect the colour I select and add it to the foregreound not the background.

Any advice would be wonderful.

Thanks.