cDOT NFS export failed, reason given by server: No such file or directory

I have a single FAS2650 running with clustered data ontap.

I created a vserver svmtest, a volume NFStest  and a policy pol_test

vserver export-policy create -vserver svmtest -policyname pol_test

Then I added 2 rules to pol_test

vserver export-policy rule create -vserver svmtest -policyname pol_test -ruleindex 1 -clientmatch @testhosts,192.168.1.0/24 -protocol nfs -rorule sys -rwrule sys   -superuser sys  -anon 65534 -allow-suid true  -allow-dev true

vserver export-policy rule create -vserver svmtest -policyname pol_test -ruleindex 2 -clientmatch hostA,hostB,hostC -protocol nfs -rorule sys -rwrule sys   -superuser none  -anon 65534 -allow-suid false  -allow-dev false

and assigned the policy to my NFStest volume

volume  modify -vserver svmtest -volume NFStest -policy pol_test

The web GUI shows everything as shown above but when I try to mount either on hostA or on a host from @testhosts or from the range 192.168.1.0/24 I get the following error:

mkdir -p /tmp/XXX
mount -vv -t nfs svmtest:/NFStest /tmp/XXX
mount.nfs: timeout set for Wed Aug  2 07:34:35 2017
mount.nfs: trying text-based options 'vers=4,addr=192.168.1.178,clientaddr=192.168.1.79'
mount.nfs: mount(2): Protocol not supported
mount.nfs: trying text-based options 'addr=192.168.1.178'
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 192.168.1.178 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying 192.168.1.178 prog 100005 vers 3 prot UDP port 635
mount.nfs: mount(2): No such file or directory
mount.nfs: mounting svmtest:/NFStest failed, reason given by server: No such file or directory

How can I troubleshoot the issue?