New world gen not working in worlds where the person did not convert the world to 1.17 first

New world gen not working in worlds where the person did not convert the world to 1.17 first.

if player starts a world in 1.16.5 then converts it to 1.18 Pre-release 1 or any of the 1.18 snapshots it dose not make world gen under y level 0

Sorry I for get that I updated the world first to 21w42a or a older version of 1.18 then updated it to 21w43a and there was no new weld gen and if you updated the world agen to 1.18 pre-release 1 there is still bedrock at y level 0.

will add pictures to show what I mean