Lxdbr0 interface is down

Hi all,
Recently I have lost the bridge interface, it turns to down state? Can anyone assist me how to analyze the process? By the way, lastly I have changed the network interface name from eno1 to eth0.
Regards.

Client version: 5.21.1 LTS
Server version: 5.21.1 LTS

To be sure I have done another bridge interface but the state is the same with the lxdbr0.

17: lxdbr1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 00:16:3e:8a:fc:86 brd ff:ff:ff:ff:ff:ff
    inet 10.187.136.1/24 scope global lxdbr1
       valid_lft forever preferred_lft forever
    inet6 fd42:4f5:461b:1ad9::1/64 scope global
       valid_lft forever preferred_lft forever