So It's now all working after a reboot. I don't know exactly what change made the difference. What I did was disconnect the downstream router, reset factory defaults, set up the interfaces using autodetect, and then configured the interfaces through WebGUI. After configuring the interfaces, I copied the two default rules from LAN to OPT1. I made an error first then corrected it. At this point LAN worked fine but I had no internet on OPT1.
Just so the family would have internet, I reconnected the downstream router since I ran out of time to work on it. When I came back to it later, I rebooted pfsense and everything now works. I thought I had tried that the night before, but I may not have after correcting errors in the copied firewall rules from LAN. (When I copied the rules I changed the interface from LAN to OPT1, but I forgot to also change the destination from LANnet to OPT1net.)
Thanks so much for all your help!
Here are the settings in case it helps someone else:
(Anything related to IPv6 or DHCPv6 is likely irrelevant for me as I don't think my connection supports it)
Interfaces/WAN:
IPv4 - DHCP
IPv6 - DHCP6
Interfaces/LAN:
General Configuration:
IPv4 Type - Static IPv4
IPv6 Type - Track Interface
Static IPv4 Configuration:
IPv4 Address - 192.168.1.1/24
IPv4 Upstream Gateway - None
IPv6 Configuration:
IPv6 Interface - WAN
IPv6 Prefix - 0
Interfaces/OPT1
General Configuration:
IPv4 Type - Static IPv4
IPv6 Type - None
Static IPv4 Configuration:
IPv4 Address - 192.168.3.1/24
IPv4 Upstream Gateway - None
Services/DHCP Server/LAN:
Enable - checked
Range - 192.168.1.100 to 192.168.1.199
Services/DHCP Server/OPT1:
Enable - checked
Range - 192.168.3.100 to 192.168.3.199
Services/DHCPv6 Server&RA/LAN/DHCPv6 Server
Enable - checked
Range - ::1000 to ::2000
Prefix Delegation Size - 48
Firewall/Rules/OPT1:
Edit Firewall Rule: (for first rule)
Action - Pass
Interface - OPT1
Address Family - IPv6
Protocol - Any
Source - OPT1net
Destination - any
Edit Firewall Rule: (for second rule)
Action - Pass
Interface - OPT1
Address Family - IPv4
Protocol - Any
Source - OPT1net
Destination - any
Settings for Verizon G1100 router:
My Network/Network Connections/Broadband Connection/Settings
Internet Protocol - Use the Following IP Address
IP Address - 192.168.1.200
Subnet Mask - 255.255.255.0
Default Gateway - 192.168.1.1
My Network/Network Connections/Network/Settings
Internet Protocol - Use the Following IP Address
IP Address - 192.168.2.1
Subnet Mask - 255.255.255.0
IP Address Distribution - DHCP Server
Start IP Address - 192.168.2.2
End IP Address - 192.168.2.199