EndPoint security with network agent version support

[WingHung]

my problem between endpoint security and network agent remote installation / upgrade problem.

Through security cloud console to remote update/installation version 12.9 of endpoint security, and that target machines is installed network agent 14.0 or 15.0.xxx version, the result return fail unstill that network agent version update to 15.1.xxx or 15.3 be success install version 12.9 of endpoint security.

is it normal behavior ?