RPi with HomeAssistant disappeared from LAN

If this is in the wrong section, I understand if it has to be moved.

I’ve been using HomeAssistant for a while now. I just changed my firewall for my LAN to pfSense (it’s running the latest current version). I use this firewall for my LAN DHCP and DNS services. I just had my first need to do something with HA through the web interface (or app) today. It’s gone. I see the RPi is still in place and appears to be working, but I can’t connect to it.

Is there some way I can still check on configuration information for HA? Check the SDCard or USB stick HA is on? (I’m on a Mac, so if it’s a Linux format, that’d be difficult.) I have a number of devices linked to my system and configured, so I want to find out how I can figure out what IP address HA is using or asking for (since I don’t have a static IP address configured in a lease).

Does HA usually request an static or specified IP address or can I assign it any address?

And is there anything I can do to find out what lease entry is for HA or any other way I can ID it in the list of leases or by reading the actual SDCard HA is installed on? (I’m figuring it does not ask for a specific IP address and that I wouldn’t have had the chance to configure it to do that when I set it up.)

Just a follow up for this:

It turns out that Home Assistant system, on a Pi, had gone bad, so it wasn’t just it not showing up or a problem with DNS or DHCP. The system had just died. (I had originally thought that couldn’t be it, since Home Assistant had performed a few automated actions after the storm that had taken several systems out.)