pfSense

I confirm that this is the case in the latest version (2.1.5).

Also there seems to be something wrong with monitors when using aliases for ports.
For example I've set up a alias named "web" with ports 80:443 and set up a HTTPS monitor expecting a 200 status.
The problem is that it's using a https request for port 80 and, of course, it replies with a 400 Bad request so port 80 is always down.
Maybe this should be a different issue ?

Just to bump, this is still the case in 2.2.3. If Daniel Onisoru's ports alias issue above hasn't been made into an issue (will check shortly), only workaround I have found thus far (i.e., have relayd keep both LB routes open/up) is to not use either an HTTP or HTTPS monitor, and instead use the relatively simple ICMP monitor (which is annoying as that's why we're using the LB in the first place. Yes, the machine may well be up, but that tells me nothing about the status of Apache...).

Bug still affecting 2.2.6, Pool Status is marked as down whenever Alias is used, even with ICMP as a monitor.

Confirmed still in 2.3_1. Use of ip alias in address field of virtual server cause " causes status "Unknown - relayd not running?"

Also: Changing alias name does not update the alias name in the load balancer virtual pool list.

Use of _ or just alpha in the alias name makes no difference.

Can confirm the bug still exists in pfsense 2.3.2-RELEASE-p1

Indeed, is still there in 2.3.2-RELEASE-p1, is not assigned to anybody unfortunately and I need to do load balancing on 2 RTP servers that initiate connection on 554 and then use any of the 65535 ports.

Can confirm it is still present in 2.4.2-RELEASE-p1 (amd64). This is really sad, the bug exists for more than 4 years now!