You can't combine different kinds of Nether planks when crafting something like a crafting table. You also can't combine Nether and overworld planks. You can do this on Java Edition.

How to reproduce:

1. Get 2 Crimson and 2 Warped planks
2. Try to craft a crafting table using your 2 crimson and 2 warped planks

Observed results:

You can't craft the crafting table

Expected results:

You should be able to combine crimson and warped planks to make a crafting table.