Google Chrome 'cast' issues in some variants of Fossapup. Can anyone explain the differences? [SOLVED]

[Phil_54]

Not sure whether here is the right place to post. Please move if needed.
I use one copy of portable chrome for various puppy installs and KLV_Airedale. @mikewalsh this is such a great gift.
I use the built in "cast" function regularly. This is found in the chrome menu.
My Smart TV works with this, even without the chromecast dongle.

In KLV and F96-CE if I cast any page it detects my smart TV (and dongle if powered up). i.e it works.

In my copy of F96_4-radky6-CE , which I assume was almost the same as F96-CE, the cast function reports no devices (even with chromecast dongle powered up)
On another laptop I have fossapup64. It also fails to cast/find any device.
There is clearly something in these puppies that is different. I'm using the same portable chrome files on a common partition.
How can I enable cast function on older puppies?

[wizard]

Make sure the computers IP address is on the same subnet as the chromecast device, or it won't be detected. Also try disabling the firewall (if it is turned on).

wizard

[Phil_54]

Just tried in F96_4-radky6-CE.
Turned off firewall, and it found my smart TV. Turned on firewall, and it now finds smart TV. (Chromecast is not powered ATM).
The firewall status seems to be a solution.
Thanks.
Can be marked as solved.