DHCP Blue - cannot ping gateway

Enabling DHCP on Blue network seems very straight forward and allowed me to allocate IPs dynamically
However I have the following major functionality issues

  1. cannot ping the gateway
    Blue subnet;
    Blue gateway :
    Cannot ping between .10 and .1

  2. cannot configure classless-static-routes
    there are other people mentioning this issue ( including me in another post)
    If anyone manage to do it, it will be appreciated if they can share details
    simply adding rfc3433 and ms advanced opting into advoptions-list was not enough
    as I got “unknown option” error
    I need to route GREEN traffic ( through BLUE gateway

option rfc3442-classless-static-routes 24, 10, 3, 1, 172, 31, 248, 1;
option ms-classless-static-routes 24, 10, 3, 1, 172, 31, 248, 1;

many thanks