Hi!
I want to ask you a question,and I want you to answer it:
did you notice something on video?
If not, I think I know what you’re doin’.
You’re doing very good with the visualiser and tissue, but when you pick up the trumpet, your old habits start to kick in. But don’t worry,the fact that you are doing good with the visualiser is already good news, don’t neglect the progress you make!
And now , let’s analyse in detail , shall we?

https://photos.app.goo.gl/dixL7b22X44mKXKN8
1. In the images 1-3 ,where you use the visualizer, everything looks normal to me. Even when you pick up the trumpet and breathe in , the embouchure has no problems ( images 4,5,6 ). Good job on that.
2. Image 7 , that is the moment you start to let the air go and make sound. Still, no problem if you compare image 7 to images 1,2,3.
3. And here it is. Images 8 and 9 ,that’s after a very short time ( a milisecond idk?), we see changes in the lips, especially upper lip , which kind of draws down and inward. That is the moment when your habits start to say hello.
On the video is more clear, but even here, if you watch and compare your upper lip in the images 1 and 8,9. In first image your upper lip RED is huge ,and in images 8 and 9 it seems to be much much smaller , after the change.

My 2 cents:
1.Be aware what you do with visualiser when blowing the tissue, repeat many times.
2. Then take the mouthpiece and do exatctly same thing, and look for the same feeling.
3. Then with the mouthpiece on your face,slide it into the trumpet (while blowing)
( P.S: These tips are what Greg said in his begginer videos.)
Don’t rush taking the trumpet when you practice. Feel your body,listen what it speaks to you.

Conclusion:

You’re on the right path if you can blow the tissue. That is something good,don’t be upset. Take a positive atitude. You will succeed if you listen carefully to the master Greg.

If you post another video,let me know 😉
-Dan.