Masking out Text in Premiere Pro 2019 I have end credits rolling over an image in Premiere Pro 19.

For a few seconds, I want a part of the image (the dog) to appear over the text. Therefore, I thought that I could mask the dog his head in the text frame, and then invert the mask. That way, only the dog head appears over the text. This worked at first. However, then I tried to apply the same formula again, somewhere earlier in the video by creating a second mask over the text, and then the effect failed. I do not understand why. I tried restarting Premiere, but it did not work.

I added a youtube video so that my settings are visible:


                
            

Thanks for all the help, in advance.
I would duplicate a copy of your background (doggy) layer.  Put it on top of your text layer, then animate the mask on your foreground layer. So in total you have three layers:

V3 - foreground dog (masked)

V2 - text credits

V1 - background dog (and everything else)


(I reckon masking like this is easier in after effects but can be done in Premiere)