What were you trying to do that didn't work?

After add the IPv4 or IPV6 address to one NIC, the  if not add the mask to the address,

for example:

[root@bootp-73-199-37 ~]# nmcli con modify con-eth1 -ipv6.address 2001:1::1
[root@bootp-73-199-37 ~]# echo $?
0

This command seems execute successfully, actually it doesn't work, but no error or prompt the user to add the mask to the ip address.  It seems only add the mask to the ip address, the command could run successfully, 

What is the impact of this issue to you?

The issue will make some customer feel confuse.

Please provide the package NVR for which the bug is seen:

NetworkManager-1.51.4-1.el9.x86_64

NetworkManager-1.51.4-1.el10.x86_64

How reproducible is this bug?

100%

Steps to reproduce

1. Add a manual ipv6 address to one NIC
2. Remove the ipv6 address with #nmcli con modify con-eth1 -ipv6.address 2001:1::1
3. Restart the network #sudo nmcli con down con-eth1 && sudo nmcli con up con-eth1
4. Check the ip status

Expected results

If the command not allowed used as #nmcli con modify con-eth1 -ipv6.address 2001:1::1, it's much better to have a error log or prompt 

Actual results

The command execute successfully, but the ipv6 address not removed.