It take too long to get the access to the shared drives after connecting with FortiClient.

[Hemin88]

When clients work remotely and connect VPN via FortiClient it takes too long to get the access to the shared drives after connecting with FortiClient, sometimes it takes more than 20 minutes show up the network drives. 

Any ideas?

Thanks 

[AEK]

Is dshared drive access the only service affected?

Does ping work? Or does it take 20mn as well?

Can you ping to FortiGate before 20mn or after 20mn as well?

[Hemin88]

Initially, I haven't noticed anything else affected, 
Ping works, 
Fortigate is reachable. 
clearing the DNS cache solved the issue but just for one time, however the client is receiving the correct IP address / gw / dns 
I checked the policies all looks good.

[AEK]

I see it is DNS related issue. So accessing the resource with its IP works fine, right?

[Hemin88]

Thank you for prompting replies. 
I was thinking about DNS as well, but since the client is receiving the correct network configuration, shouldn't it work just fine?

[AEK]

If you can access the resource via its IP (not hostname) then you VPN is basically fine.

You can still check if your split DNS is enabled and working fine in order to correctly access the resource via its hostname, by testing with dig or nslookup. E.g.: dig host.internaldomain.com

If it gives the right IP then the split DNS is working fine, and the 20mn delay may be due to the fact that the host.internaldomain.com is defined in both public DNS and private DNS.