Player permission when joining from invite not overriding the world permissions which are not changeable because it is removed from realm downloaded worlds. I have the permission on my realm set to the member, so:

Expected Behavior:
People join in members and the realm overrides the world's settings.

Observed Behavior:
People join in either visitor or member.

I haven't fixed the issue in the world yet, but if anyone knows where this permission saves in the level.dat, please comment. I posted the level.dat of that world below as a screenshot.