@JG75 I have the exact same issue. It's weird, all the wireless clients connected never gets any issues, but the device that is wired is the one who has issues with the lease. I haven't figure out a workaround yet

@scaffnull I used to have a similar problem. I solved it by setting the DHCP leave to 1440 minutes, which helped the wireless clients. For the wired clients I used manually assigned address. I set the DHCP pool to be 192.168.0.2 - 192.168.0.200 and used 201+ addresses for the manually assigned clients. 

@M____ Thanks! I will check this out. What I've tried before is to assign the wired computer a IP address outside of the DHCP pool (on his computer). But then I don't get any response from the router, so I can't ping the default gateway or anything. But you are saying reserve an address with the devices MAC and an IP address outside of the DHCP pool, then set the static IP address that matches the reserved address on the router?