new device in network shows as 'offline' and access to it is limited

[bongo]

i added some new devices (shelly) to my network. there are already quite a few of these devices running for a long time without issues.
so the new devices are connected exactly the same way as the old ones are and all configuration is the same.
the new devices connect to the network without issues and get the IP address as configured in opnsense under services DHCPv4, but when checking the leases, they all show as 'offline'.
as long as i am within the same LAN as the devices (LAN1), i can access them without any problems, but when i try to access them from my other LAN (LAN2) through opnsense, they are not accessible (this works fine for all other shelly devices in LAN1). i am quite sure that my configuration is correct, as i just added the IPs of the new devices to the existing group.
with packet capture on the interface, i can see that the packets to access the devices, sent from LAN2, pass the interface of LAN2 but never appear on LAN1.
the 2nd issue is, that the new devices try to access shelly cloud to do a firmware update, but they are not able to connect to the internet.
i 1st thought that i have some kind of routing issue on opnsense, but now i'm qite sure that the reason for the issues is, that opnsense thinks that the devices are offline (as shown in the leases list of DHCPv4).
so the question is: why does opnsense think that these devices, it gives an IP address to, are offline?
btw: it's not just 1 shelly device. i have this issue with several devices of different type, so i do not assume a defective shelly.
thank you for any advice on solving the issue!

my actual version is OPNsense 25.7.11_9-amd64.

[bongo]

some additional information:
when checking Interfaces: Diagnostics: ARP Table, i realize that all new devices are missing, although i ticked the ARP Table Static Entry box when registering in DHCPv4.

[bongo]

looks like a reboot of opnsense solved the issue ;-)

[chemlud]

Can confirm problem and solution. Switched the MAC for a static DHCP client (have static ARP on that interface enabled btw). IP is handed out, traffic on same interface going back and forth, but no DNS, and no other traffic outside the same interface going back and forth. Client not showing up in ARP table and listed as status "offline" in DHCP leases.

Took me some hours to find this here and a reboot of OPNsense resolved the problem immediately. Strange, very strange.