The bug

20w13b, Mojang names

The method net.minecraft.world.item.CompassItem.getLodestonePosition(Level, CompoundTag) checks twice if the item compound tag has a LodestonePos tag. One of these should probably be a check for the LodestoneDimension tag.
However, that check is not needed because the called method CompassItem.getLodestoneDimension does not fail if the tag does not exist.