SEP 11.x is end of support life and you will no longer receive defs for it.
Further info here:
https://www-secure.symantec.com/connect/forums/symantec-endpoint-protection-110x-eosl
https://www-secure.symantec.com/connect/blogs/did-you-get-security-memo-symantec-endpoint-protection-11-eosl
You may still receive untested defs from a 12.1 SEPM but this is taking a risk and not guaranteed. Best to move to 12.1.5 now.
Saem thread here from earlier today:
https://www-secure.symantec.com/connect/forums/symantec-endpoint-definition-not-updating