I could not go a day without connecting with my kids in some way. 10 days is very long. It is either heartbreaking for him and he is disconnecting.This should not be up to d11 to contact. He should.
The household chore thing could be like my W's laundry thing. He could be missing the homestead too but uncomfortable if you are there. Just definitely keep tabs on what is yours and call him out on anything odd.
D11 needs his attention though.

M17 yrs.
me49
xW47
d15
d11

BD1-Jul/11(Affair found out)
Therapy 9 months (tried 2)
BD2- May/12(sep)
Court Jul/13 - I got 50/50
Sold home - Aug/13
Court #2 - Dec/13
Court#3 - Apr/14 ... She lost again
We settled.