I am sorry for the delay, as I was having account troubles. I am not able to add a screenshot at the moment, but I can walk you through steps to recreate it:
Go to 3 by 3 crafting grid
Go to recipe book
Use it to craft a shield
note that the recipe book requires six oak wood planks and an iron ingot
Now try to manually place another wood type in the crafting grid in the same pattern
Other wood types do not work
I hope this will help in recreating the issue.
I have tried to recreate this bug in the latest version, and it does not appear. You can now make shields using any wood, even a mix of different types. I will close this ticket as it has been resolved. Thank you.