Vivaldi: No sound while streaming from within the sandbox

[Eternalbeta]

While casting my computer screen with Vivaldi browser running in a standard (default) sandbox there is no sound on my TV, with Vivaldi out of the sandbox however, there is no problem with sound. Looking at all the sandbox options and postings in the forum I can’t seem to find any working solution for this. Just to be clear, the Vivaldi browser is installed on the laptop, not in the sandbox.
It would be great if someone could help me by pointing out what option I should activate or what else I should do to get sound up and running as the sheer number of options are rather daunting if you do not fully understand the implications of each.

Vivaldi Version7.9.3970.60 (Official Build) (64-bit)
Chromium Version146.0.7680.218Extended Stable channel
Channel Official Build
Platform / OS Windows 11 Version 25H2 (Build 26200.8117)

Sandboxie-plus v1.17.5 INI Section:
Enabled=y
ConfigLevel=10
AutoRecover=y
BlockNetworkFiles=y
Template=OpenSmartCard
Template=OpenBluetooth
Template=FileCopy
Template=SkipHook
Template=BlockTelemetry
Template=BlockPorts
Template=LingerPrograms
Template=AutoRecoverIgnore
Template=OpenSmartCard
Template=OpenBluetooth
Template=SkipHook
Template=FileCopy
Template=BlockPorts
Template=LingerPrograms
Template=AutoRecoverIgnore
Template=Vivaldi_Profile_DirectAccess
Template=Vivaldi_Phishing_DirectAccess
Template=Vivaldi_Sync_DirectAccess
Template=Vivaldi_Preferences_DirectAccess
Template=Vivaldi_Bookmarks_DirectAccess
Template=Vivaldi_Force
RecoverFolder=%{374DE290-123F-4565-9164-39C4925E467B}%
RecoverFolder=%Personal%
RecoverFolder=%Desktop%
BorderColor=#ff5500,ttl,6,192,no,6
AutoDelete=y
CustomColor=y
FakeAdminRights=y
DropAdminRights=y

 

[Eternalbeta]

Anybody who can help me?

 

[bastik-1001]

Anybody who can help me?

I don't know how I might be helpful, but for testing, you could try if it works in an application compartment box. Create a new sandbox, select Application Compartment as its type (the green icon) and check whenever streaming audio works. Since that is a feature behind a paywall, it is just meant as test.