I have tried to create a portal to the nether but it doesn't work, it catches fire but the portal is not created. From nether to overworld doesn't work either. It has happened to me in 1 player and in server (aternos).
Version forge 33.0.2
Version Minecraft 1.16.2
https://gyazo.com/44eb9500da81950834bee62f3392ff8f