There are many posts here and on the www in general indicating that screen mirroring (casting, connecting) from a Laptop or PC fails to connect to the Roku. The connection starts, then about 1/3 of the way through, the connection status bar on the Roku connected TV just stops. After a while the connection fails on the PC/Laptop.
Given that your Roku is properly configured for screen mirroring,
The cause may be the Firewall on your PC/Laptop (I.E. Antivirus App).
To check if this is your issue, FIRST try turning off the Firewall in your Antivirus. How to do this depends on your Antivirus App.
If that works and your PC/Laptop now connects, THEN you might proceed with the following which should allow you to leave your Firewall active and still connect/cast/screen mirror to the Roku:
I added a range of IP addresses allowed and now my PC/Laptop will cast/connect and screen mirror to my Roku - with the Firewall active. There may be a similar process with other Antivirus Apps.
Disclaimer. I do not know if this action is totally safe. Proceed at your own risk. However it should be better than just disabling your Firewall.
This is for my current version of McAfee:
- Open McAfee and select the My Protection Icon (four dots in a square or other method)
- Under Protect your PC, select Firewall
- Scroll down and select My Network Connections.
- At the bottom of the list click on Add
Add this range of IP address Start 172.16.00 End 172.31.255.255
- Add this range Start 172.29.243.224 End 172.29.243.255
- Be sure to select Home Network - that should still protect those IPs from external connections while allowing on your home network.
- Save the work, turn your Firewall back on and you should be good to go.