I don't know about Leela 11, but Leela Zero knows how to kill White on the left; it just prefers to let White live and make thickness in sente. (I tried a couple of different networks and the amount of preference varied.) I showed it the position after the kill, to be sure it was evaluating the right thing.
Edited to add: This does not mean that killing White on the left is "incorrect" or a bad idea!