Hello @Nealjane
Thanks for posting here in the Community!
For clarification, does your Roku device automatically disconnects to the wifi causing it to buffer? Are you getting an error code or message? If so, refer to this link for common Roku error codes and their recommended actions: What should I do if I cannot connect to my home network or the internet?
Furthermore, please be advised that Roku Express is only compatible with wireless b/g/n networks on the 2.4 GHz spectrum. Ensure that your router is broadcasting a 2.4GHz Wi-Fi network for the device to connect to.
You can also try configuring your router and use wireless channels 1, 6, or 11. Each time you change the wireless channel, you will likely need to apply/save changes before you are prompted to restart the router.
Please keep us updated.
All the best,
Kariza
Kariza D.
Roku Forum Moderator