Affects Version/s: 20w17a
Fix Version/s: None
Environment:Windows 10 Home x64
Java v8 u251 build 1.8.0_251-b08
16GB DDR4 RAM
GTX 1050 4GB
Intel i7-8750H @2.2GHz, clocked to 4.4GHz max, 6 core 12 thread
Tested dark oak saplings acquired through all known means (/give, Creative Inventory and through direct dark oak leaf drops) on both naturally generated and manually placed dirt and grass, both in sunlight and not, with all appropriate requirements met. Saplings will not grow, even with enhanced tickrate gamerule or with copious amounts of bone meal.
Have also tested 1x1 (alongside the normal 2x2) setup of dark oak sapling in case of unannounced change to dark oak mechanics, with no success.
Reproducible with ease, simply use any dark oak saplings as would normally be intended; they will never grow.
All tested in single player only.