This actually appears in past MCR versions too but i Think I have discovered the problem of this, also found some other bugs related to Procedures
first we know that going threw custom dimension portal on survival moves you to different location than portal is placed
I have did some search and probably discovered the problem, problem is in coordinate conversion which in nether is 1:8 block of movement because in nether we move equivalently to 8 block in overworld but the main point is that in MCreator case this works only half way, our portal is created but we are not teleported to this portal or to equivalent coordinations or simply portal switches dimension but coordinations stays the same "Attaching screenshots to compare"
now about Procedures because there are several problems with them
1. Switching Dimension by procedure makes minecraft stuck on loading terrain "No matter if its pregenerated" after restarting MC and opening world it works fine
2. Entering Threw Procedure to different dimension generates Nether Portal in it
3. Entering new dimension in Creative mode have same results to entering it threw portal in survival, does not change coordinates
This are all the stuff I found on this and I'm quite sure that this bug is related to 1:8 Coordination Conversion