Twisting Vines and Weeping Vines drop rate is not affected by the Fortune enchantment

Steps to Reproduce:

1. Enchant a tool with Fortune 3
2. Place down some twisting vines and weeping vines
3. Switch to Survival mode
4. Break the vines with the Fortune 3 tool

Observed Results:
The drop rate is not 100%.

Expected Results:
The drop rate should be 100%.

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Original Description:
According to the wiki, twisting vines should drop more often with the Fortune enchantment. It says with fortune 3, the drop rate becomes 100%. Using a Fortune 3 axe, and hoe, the twisting vines rarely dropped (seemingly below 33%, but definitely not 100%). They did drop 100% of the time with Silk touch (didn't test with Shears).