Before you ask, fast render was disabled.
I'm wondering whether this is a BOTI problem or just a dimension problem since it's happened both when I entered and when I opened the door on two separate occasions.
Recently I got optifine and BSL Shaders https://bitslablab.com/ and when I entered TARDIS at first I thought it froze, but I when I paused the game I could see the mouse. So I clicked roughly in the area where the quit to menu button is and it did the usual loading screen but the main menu was replaced by the image of when I entered the TARDIS. I hope that makes sense, because I tried uploading a video and it didn't work lol
Shaders have fast render on. Shaders and BOTI do not and never will work together. Shaders don't "understand" the dimensional engineering.
to slightly correct this, shaders need Fast Render Off to work, but shaders themselves change the rendering system in a way that it cannot interpret OpenGL Stencils