I have a home server, running Ubuntu which has five NFS4 shares. I can't mount two of them in Deepin 15.3, because the server's firewall blocks the request, but three of them are working perfectly. All the NFS shares start to work if i disable Ubuntu's firewall. Yes, Ubuntu-related problem. But people at that Ubuntu forum I asked about this, say that the problem is I use a Chinese OS and this is the chinese people's fault. What can I do to find out wether this is a Deepin or an Ubuntu-related issue?

Here's the full output of dmesg on Ubuntu (the people at the Ubuntu forum has requsted the full output): https://paste.ubuntu.com/24236901/
Also Ubuntu can mount Deepin's NFS share even when both machines' firewalls are enabled. And another Ubuntu machine can't mount the NFS shares of the home server, but can mount Deepin's NFS share and vice-versa (after installing nfs server to Deepin and the other Ubuntus and configuring a few NFS shares on all of them for testing).