I've created a world two years ago and I've had a shader on it but with the last update, the shader don't work. I've also test on another world but it's the same. Just the shader don't work but the texture pack change also the glasses texture and that works.
MCPE-155826
Shaders
Resolved
Invalid
0
The Render Dragon engine currently does not support third-party shaders. If you would like to see support for third-party shaders, please add a vote to this thread on the feedback site:
https://feedback.minecraft.net/hc/en-us/community/posts/360077420452-3rd-party-shader-support-for-render-dragon