I just found out about this bug, 6 minutes after 1.19 released, in 1.19-rc2. I'm marking it as 1.19, as it is the same version.
Jungle Leaves don't drop Jungle Saplings, at all. I mined about 100 of them, and got exactly zero of them.

This is the issue's original description.
I created it because I mined 100 Jungle Leaves, and got zero saplings.
This issue is problematic because

• It's just very hard to get Jungle Saplings
• People may think this is a bug
• This is inconsistent for no reason, as Tropical plants tend to create more seeds, and spread faster, than other plants, unlike current implementation where it's nearly impossible to plant Jungle Saplings, because of their rarity

I would suggest to

• Make the drop chances as high as the other trees
• Increase the chances, not to a level of the other trees, but enough to keep the mechanic but remove the annoyance.