SEP 11.0.7 can't update virus definition from SEP12.1.4

Dear All,

I have a problem about SEP 11.0.7 can't update virus definition from SEP12.1.4.

Prevously, I use the SEP 11.0.7 and I upgraded to SEP 12.1.4.

The clients 70% still use 11.0.7 and 30% has upgraded to 12.1.4.

I have problem only version 11.0.7 but SEP 12.1.4 can update normally.

SEPM has normally update. I test by move client version 11.0.7 to other SEPM, it's can to update virus definition.

(I have 2 SEPM cluster.[DC and DR])

I'm so confuse.

Thanks.