Is this a bug?

I noticed the same thing... Probably a bug...

Should be fixed in upcoming beta versions.
There is still bug that addresses may be lost on interface name change, but this will be fixed in future releases as well.

Sometimes veth can be lost automatically.

Sometimes veth can be lost automatically.

please explain this in more detail, and if possible provide steps how to repeat this, as i haven't seen such issue.

Sometimes veth can be lost automatically.

please explain this in more detail, and if possible provide steps how to repeat this, as i haven't seen such issue.

Sorry, I have no idea how this happened, maybe after I created veth2，or disable/enable veth interface through UI (as this title said it's a bug), ip address turned to 0.0.0.0/0. I didn’t realize it was a bug at the time.
But I really encountered the problem of automatic deletion of interfaces twice.

Not 100% sure on what's going on here. But the format of IP address changed types as result of adding IPv6. It used to take a plain IP address (172.18.0.1), but it now requires a CIDR subnet (172.18.0.1/24) be stored in config. So I think the upgrade doesn't change the config, but winbox does expect the config to have the CIDR style address. So 0.0.0.0/0 is when it cannot parse the plain (no subnet) address.