それでも彼には、自分のことだけはわからない。
I'm translating the above sentence from Japanese to English, and I'm having issues with understanding what だけはわからない means.
Why does だけ come before は? says that だけは means 'at least'; and https://jisho.org/search/だけは supports this with a definition of 'at least not (when followed by a negative)'. I know that わからない means 'to not understand' as its わかる in the negative form. When I tried to translate the above, the resulting sentence made barely any sense (Example 1) or it failed to convey the 'abstracting focusing' aspect of のこと (Example 2).
Example:
1) Even so, he understands anything but not what is only about himself.
2) Still, he at least doesn’t understand himself.
What do I need to know in order to properly understand what だけはわからない means in the above sentence?