Tailscale issues - not connecting

[d82k]

Hello,

I have an issue with Tailscale.
I have configured Tailscale on two OPNSense to establish a site-to-site connection and this was working great. Plus from my mobile phone I could access both subnets published by the OPNSense and use either of the two as exit node.

I suddenly realized this was not working properly anymore, not sure if it was one upgrade of the Tailscale or OPNSense.

I realized that in the OPN Dashboard Tailscale reports the the agent Green but Online "No" following:

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looking at the details in VPN: Tailscale: Status > General I see the agent running

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under VPN: Tailscale: Status > Peers I see the other connected peers

On the Tailscale website this shows the OPNSense nodes offline.

If I reboot OPNSense this stays online and shows online on the Tailscale website only 10 seconds.

The other wired thing is that with a previous version of the app/agent, although the OPNSense was clearly offline on the mobile app and the website console, while being on a public network I was able to reach the OPNSense from my mobile (via Tailscale). Now it's no more the case.

Any idea or test I can run please?

Kind regards,
dk

OPNSense version: 25.1.10
Tailscale version: 1.84.2