The extension says this tab cannot be protected.
Chrome and Brave do not allow tab capture on internal pages such as chrome:// or brave://, or on extension-store pages. Try a standard website that is actively playing audio.

Sonic Shielding support
Start with the checks below. If the issue continues, report it with the browser version, page type, and what you expected to hear.
Common questions
Chrome and Brave do not allow tab capture on internal pages such as chrome:// or brave://, or on extension-store pages. Try a standard website that is actively playing audio.
Protection stays active for a tab once enabled, but each additional tab must be enabled separately from the extension popup.
Keep Preserve speech enabled, reduce protection strength, disable aggressive alarm blocking, or lower reductions in the optional comfort EQ.
Increase tone-detection sensitivity or maximum tone reduction, lower the minimum protected frequency, or try aggressive alarm blocking with care.
Sonic Shielding only processes audio from protected browser tabs. It cannot intercept operating-system notifications or desktop apps.
Still need help?
Do not attach private audio or sensitive health information. A description of the sound, your browser version, and steps to reproduce the issue is usually enough.
Use care with sound. Begin at a low volume and stop immediately if anything feels uncomfortable. Sonic Shielding is a comfort tool, not a medical device or hearing test.