Attaching a second network to a Docker NGINX container causes it to stop responding to any of them

Question

I've been trying to setup what might be a rather complicated docker setup, and have run into a very weird issue. What I currently have is a collection of containers, all running different web services, and an Nginx container that routes them to be publicly accessible over HTTPS. This has worked fine, but meant I can only setup services that use HTTPS, and was run over one of my 5 static IPs my ISP has given me, by routing it through my UniFi network. When I went to add GitLab, I realized I needed to connect it to a separate public address, so that I could access port 22 for SSH based Git clones. Since I already had the switch port connected to my modem on a vlan (topology weirdness, it works fine,) I simply tagged the server port to allow that VLan through, and started using a macvlan network. As soon as I added the macvlan to my nginx container, it stopped working all together. After spending several hours making sure my static ips were actually setup correctly, I found out that if I attach more than one network to my Nginx server, it stops responding to anything at all. If I stick just the macvlan on it, it can respond just fine, even over my static ip. But if there is more than one, everything stops working. Pings, TCP requests, everything. If I use docker network disconnect to remove the network from the running instance, it starts working immediately again. I've tried this with just netcat on an alpine instance, and can confirm that all inbound traffic stops immediately when a second network is attached, and resumes as soon as it's removed. I'm including a sample docker-compose that shows this effect just by adding or removing the networks.

docker version:

Client: Docker Engine - Community
 Version:           20.10.13
 API version:       1.41
 Go version:        go1.16.15
 Git commit:        a224086
 Built:             Thu Mar 10 14:07:51 2022
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.13
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.16.15
  Git commit:       906f57f
  Built:            Thu Mar 10 14:05:44 2022
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.5.10
  GitCommit:        2a1d4dbdb2a1030dc5b01e96fb110a9d9f150ecc
 runc:
  Version:          1.0.3
  GitCommit:        v1.0.3-0-gf46b6ba
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info:

Client:
 Context:    default
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)
  buildx: Docker Buildx (Docker Inc., v0.8.0-docker)
  compose: Docker Compose (Docker Inc., v2.2.3)
  scan: Docker Scan (Docker Inc., v0.12.0)

Server:
 Containers: 1
  Running: 0
  Paused: 0
  Stopped: 1
 Images: 9
 Server Version: 20.10.13
 Storage Driver: zfs
  Zpool: Storage
  Zpool Health: ONLINE
  Parent Dataset: Storage/docker
  Space Used By Parent: 87704957952
  Space Available: 8778335683049
  Parent Quota: no
  Compression: off
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux nvidia runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 2a1d4dbdb2a1030dc5b01e96fb110a9d9f150ecc
 runc version: v1.0.3-0-gf46b6ba
 init version: de40ad0
 Security Options:
  apparmor
  seccomp
   Profile: default
 Kernel Version: 5.4.0-104-generic
 Operating System: Ubuntu 20.04.4 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 12
 Total Memory: 39.18GiB
 Name: server2
 ID: <Redacted>
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: No swap limit support

EDIT: forgot to add the docker compose file. Here it is:

services:
  nginx:
    image: nginx:1.21.6-alpine
    networks: 
      public_interface:
        ipv4_address: 123.456.789.102 //Replaced with nonsense for privacy reasons
      private_interface:
        ipv4_address: 192.168.5.2
      web_interface:

networks:
  web_interface:
  public_interface:
    driver: macvlan
    driver_opts:
      parent: enp10s0.100
    ipam:
      config:
        - subnet: 123.456.789.101/29 //Replaced with nonsense for privacy reasons
          gateway: 123.456.789.108 //Replaced with nonsense for privacy reasons
  private_interface:
    driver: macvlan
    driver_opts:
      parent: enp10s0.305
    ipam:
      config:
        - subnet: 192.168.5.0/24
          gateway: 192.168.5.1