Gradient behavior is PS CC

[fabbui]

Maybe I am doing somthing wrong here. I had been working with PS for a while and then had a couple of months break. Now back to it. Working with PS CC 23.3.1, Windows 11. 

I like using the gradien with Blank and white (forground/bacground)  when working with Curves when adding some sort of vignette. I like this way as it allows me to control the shadow areas better. So my process is , 

1. Add the curve

2. Invert the mask (all black now) 

3. Use the gradient  from the cornes and sides in  to mark the sides with white on the mask layer. I do this mostly for all 4 corners/sides (kind of). 

Problem I have now is that every time I use the gradient it removes my previous gradient application instead of adding to it. I tried with foreground to background (and White/black) colors, also using foreground to transparency.  

It used to work up until recently. I am not sure if I am missing a setting or an option. Any ideas?

[Semaphoric]

Try setting the Blending Mode of the Gradient tool to something other than Normal, such as Multiply.

[Bojan Živković]

If nothing else help, you may want to try with preference reset what is medicine for all things weird in Photoshop Preferences in Photoshop (adobe.com)