Custom nether wierd issue

Hey all, I'm currently trying to use a custom dimension i downloaded from modrinth as the nether for my world, I already worked my way around the files and folder to make sure the nether points to this dimension instead of vanilla nether. My issue is this, I can make a nether portal and light it with no issue, but I can't go through it, it just never loads teh other dimension. I can use the /execute in the_nether run tp ~ ~ ~ command to teleport myself there with no issue but as soon as I enter, I take damage as if I was standing in the void. Could anyone point me in the right direction to fix that? Using the dimension normaly (not replacing my nether) works with no issue.