RHEL8, CIFS: Subdir is not remounted after share failover

Issue

• Subdir testdir exists on both DFS targets. we mount it :

[root@rhel8 ~]# mount -t cifs -o username=roberto,password=mypass //172.23.1.225/dfs/dfslink/testdir /mnt
[root@rhel8 ~]# grep cifs /proc/mounts 
//172.23.1.225/dfs/dfslink/testdir /mnt cifs rw,relatime,vers=3.1.1,cache=strict,username=roberto,uid=0,noforceuid,gid=0,noforcegid,addr=172.23.1.208,file_mode=0755,dir_mode=0755,soft,nounix,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=60,actimeo=1 0 0
[root@rhel8 ~]# ls -l /mnt
total 0
-rwxr-xr-x. 1 root root 0 Mar 12  2020 testfile

• Now after a forced failover (note how server address changed):

[root@rhel8 ~]# grep cifs /proc/mounts 
//172.23.1.225/dfs/dfslink/testdir /mnt cifs rw,relatime,vers=3.1.1,cache=strict,username=roberto,uid=0,noforceuid,gid=0,noforcegid,addr=172.23.1.192,file_mode=0755,dir_mode=0755,soft,nounix,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=60,actimeo=1 0 0

• But testdir subdir is not mounted but root of the share, although it exists:

[root@rhel8 ~]# ls /mnt
dir1  testdir