It worked after following your suggestions:
Changing IP-range of my OPNSense router for the LAN network.
Disabling the "Block private networks" and "Block bogon networks" on the WAN interface.
Thank you all for your quick and swift answers.
Changing IP-range of my OPNSense router for the LAN network.
Disabling the "Block private networks" and "Block bogon networks" on the WAN interface.
Thank you all for your quick and swift answers.