Can't mount home shares with NFS after a NAS restart

I can't mount the users' home folders with NFS if I don't toggle NFS access off and on again after a system restart. Showmount shows

root@Io:~# showmount -e 127.0.0.1
Export list for 127.0.0.1:
/run/nfs4/data                *
/run/nfs4/home                *
/home                         *
/run/nfs4                     *
/data/Video                  192.168.0.0/24,127.0.0.1
/run/nfs4/data/Video         192.168.0.0/24,127.0.0.1
/data/Pictures               192.168.0.0/24,127.0.0.1
/run/nfs4/data/Pictures      192.168.0.0/24,127.0.0.1

so home is exported. Both users' UIDs and GIDs on the NAS match that on my computers.

I mount the shares with

Io:/home/user10 /home/user1-k1/NAS nfs4 rw,user,noauto,bg,hard,intr,_netdev,timeo=5,retrans=5,actimeo=10,retry=5,proto=tcp 0 0
Io:/home/user20 /home/user2-k1/NAS nfs4 rw,user,noauto,bg,hard,intr,_netdev,timeo=5,retrans=5,actimeo=10,retry=5,proto=tcp 0 0

All works fine untill the next NAS restart and I have to log in to Web UI, toggle the home shares NFS access off and on to be able to mount the home folders localy.

BTW, is there any reason the home share is exported with a wild card, opposite to the other shares where it's possible to restrict access to some computers on the network? The problem was raised 4 years ago in Systemic NFS problems , but it's still there.