Some clients not using the DNS Suffix Search List which is applied using GP

Hello,

I have a domain with a number of clients however they are not using the DNS Suffix Search List which i have applied using group policy.

I can see that the policy has applied and the DNS Suffix Search List shows up correctly when i look using ipconfig /all.

for EG:

I have a search list of 3. domain1.local, domain2.local and domain3.local.

My primary dns suffix is domain1.local.

I ping a server who's record is in domain2.local DNS zone however after a pretty long pause it does not resolve and errors out with "ping request could not find...". If i ping using FQDN then it works fine.

The DNS Suffix Search List of the client has all of the domains listed so should look through this list before throwing the 'cannot find' error.

What is going on here?