Problems with interface changes - admin UI hangs, existing connections too

[madbrain]

I have 3 WAN interfaces and one LAN interfaces. The WAN is setup with a load balancing rules. More details about the configuration are in the thread at https://forum.netgate.com/topic/187957/netflix-buffering-with-3-wans .

Sometimes, I will disable one WAN interface and enable the others. For example, I just disabled COMCAST and enabled SAIL and VERIZON, which were both previously disabled. I hit "save" in the UI for each of the 3 configuration changes, then clicked "apply". I waited several minutes, but the action seemingly never completed. Firefox seemingly hanged. I clicked "apply" again, but got the following message :

"The following input errors were detected:

The settings have already been applied!"

In addition, I was trying to reload a page in another tab in Firefox while the WAN changes were ongoing. The page reload also hanged. After the second "apply" in the admin, I was able to reload successfully. I'm not entirely sure if this is working as designed or not in this case. Obviously the HTTP connection was initiated on one WAN, the COMCAST WAN, which got disabled. The connection couldn't be resumed on the other WANs. It would have to be reopened. But it wasn't seamless. Maybe there is a way for pfSense to signal that and interrupt the connection for this case.