Block state autocomplete does not work unless you put a space between block name and first bracket

How to reproduce

/setblock ~ ~ ~ oak_log[

Press tab

Expected result
It auto completes the "axis" state

Actual result
Nothing happens, it only works if you type oak_log [

Notes
Putting a space between the block name and states is not Java Parity, so that syntax should be disallowed, not required.