LAN DHCP issue

Hey fellas

I've got an openwrt v21 mips router and win10 machine at my old home (inaccessible, don't ask).

The win10 machine started displaying problems to renew its IP from the router. I tracked down the problem to the clock being wrong on the windows machine. It was off by a few hours, maybe a day. I think the bios battery is empty. Automatic internet time under microsoft doesn't work. I manually set the time and DHCP was fine for a couple of weeks.

I was able to remote into it via Teamviewer even without an IP so I assumed it was running over ipv6 which the machine still got. That's how I set the time.

Now months later I don't even see an ipv6 address under the router's dhcp leases and even Teamviewer reports the machine as offline. (I'm able to tunnel in to the router)

I know the lan port on the machine is running because my linux VMs are up and running (on the very same adapter).

Anyway. I was wondering if openwrt has some kind of setting that allows dhcp to assign ip addresses regardless of timestamp? Or maybe there isn't a timestamp. The machine stopped requesting IPs?

I'm thinking to ask my friend to restart the machine and then if accessible I'll set a static IP.

Thanks for reading and/or commenting.