Laptop has IPv6 connection but no IPv4 connection

[RammsteinFS]

My Windows 10 laptop is able to establish an IPv6 connection from our broadband hub but it has suddently started struggling with getting an IPv4 address from the DHCP server.  I have tried ipconfig /renew and it can't establish a connection for a DHCP address, even though the laptop has a connection to the network (via IPv6 address).  I only experience this problem when trying to connect to the Sky router and my other devices (iPad, Android phone, Raspberry Pi, etc) have no problem.  The router settings can't show me anything specific so I wondered what the problem was.  I also see that someone else on here has had the same problem recently.

Thank you.

[jamesn123]

@RammsteinFS 

Could you point us to the other post thats had a similar problem? I havent seen it

The inital testing from yourself would suggest a problem with your PC itself if all other devices can get an IPv4 lease successfully. 

[RammsteinFS]

I can't add a hyperlink or show the thread number but the title of the other post is "I Have IPV6 But My IPV4 Connection is not working".

Like I said, my laptop can obtain an IPv4 address on other networks and the connection is fine - it even works using my phone's hotspot.  There are two other laptops on our Sky home network that are having the same issues.

[FLC]

@RammsteinFS 

Have you tried setting a static IP address on the laptop (not an IP reservation on the router)?

IIRC, that means changing the DHCP range on the router as it takes the whole address range by default. So assuming your router is on the default 192.168.0.1 address, cap the DHCP server at say 192.168.0.100 & then set a static IP address on the laptop above 100.

[RammsteinFS]

I have tried that.  The router is showing that the laptop has connected with the assigned IPv4 address, but the laptop is showing a completely different address  (outside of the LAN) and can't ping the router. 

Do Sky router's use different protocols than alternative networks?  I tried using Wireshark but couldn't see anything specific other than lots of ARP requests for other IP addresses.