Hello, I am hosting a server for some friends and when ever we try to create gunpowder from flint using the combustion heater it makes th eflint into blaze powder instantly.

This was fixed in version 2.3.4 of the mod a couple days ago. If you're using an older version and playing a pack, wait for it to update.

If you are using version 2.3.4, then let me know.