Help with OPNsense - GUI Access and DHCP Issues

[Dinez]

My Setup

    CPU: Ryzen 3950x
    RAM: 32GB
    Storage: NVMe drive for VMs and Proxmox
    Network Card: Realtek RTL8111/8168/8411 PCIe gigabit ethernet card (2 slots)

The Issues I'm Facing
1. No GUI Access or DHCP

Sometimes, I lose access to the OPNsense GUI, and devices on my network can't get IP addresses from the DHCP server.
I checked the DHCP logs and found these two lines repeating over 100 times:

<190>1 2024-11-04T20:00:57+00:00 OPNsense.localdomain dhcpd 62074 - DHCPDISCOVER from 50:2c:22:22:22:72 via re0

<191>1 2024-11-04T20:02:24+00:00 OPNsense.localdomain dhcpd 62074 - reuse_lease: lease age 1 (secs) under 25% threshold, reply with unaltered, existing lease for 22.22.22.12

It seems like devices are stuck in a loop asking for IPs, but I can't figure out what's causing it.
2. Massive DNS Queries in Pi-hole

My Pi-hole instance logged 6,000 queries in just 5 minutes, which feels way too high for my small network. I haven't identified where this traffic is coming from.
3. Issues After Installing Zenarmor

I installed Zenarmor, but after the installation, I completely lost access to the OPNsense GUI.

    I rebooted the firewall multiple times, but it didn't help.
    Finally, I manually re-assigned the LAN interface its old IP, and that restored access.

4. LAN Network Dropped After Plugging a Cable Back In

Yesterday, I unplugged a cable for a corporate computer from the switch while troubleshooting. This morning, I plugged it back in, and the entire LAN network went down. I lost GUI access and DHCP services again.
What I've Tried So Far

    Checked DHCP settings (lease time, ranges, etc.), and everything looks normal.
    Rebooted OPNsense and my Proxmox host multiple times.
    Verified Pi-hole settings, but I couldn't identify any misconfigurations.

Questions

    Could these issues be related to my Realtek network cards? I've read they can cause problems, but I don't know how to fix this if that's the case.
    Could Zenarmor be interfering with DHCP or GUI access?
    What could be causing the massive DNS queries in Pi-hole? Could it be a misbehaving device or a loop?
    Why would plugging in a single device bring down my entire LAN network?

Any Advice?

I'd really appreciate any tips or suggestions for debugging these issues and improving my setup. Thanks in advance! 😊