nanoDLP

I've run into some issues during my work with the nanoDLP mask,

after measuring the values of the projector, and creating the greyscale mask, I added a STL file that is a rectangle that covers the whole building area, I added the PNG image to the STL file when uploading it to the plates, I measured the UV intensity and The mask is working, However, I tried using my PNG mask as a global mask so that it gets applied automatically after each plate uploaded, I went to the setup page, then to Projector Mask, chose my image then pressed on add mask, then submit(i double checked that my mask was uploaded and it is clearly visible in the projector mask page).

Then I tried re-uploading the STL file but this time without the mask chosen in the add plate page, I then measured the UV intensity to find out that my mask no longer work.
Is there is any way I can apply a mask that is global to all STL files, without the need to upload the mask with each STL I add?

Best regards,