web-ext run --target chromium \
  --chromium-binary "/usr/local/bin/chromium" \
  --args="--user-data-dir=/Users/xxx/Library/Application\ Support/Chromium" \
  -s /Users/xxx/.output/chrome-mv3-dev

web-ext version: 8.9.0
OS: macOS 26.0 Beta (25A5351b)

When I launch Chromium using the above command, Google treats the browser as "unsafe."
This causes a lot of trouble, not just google account login failures:

Google Search always requires CAPTCHA verification.

YouTube videos stop after a few seconds, and captions cannot be loaded.

Since my extension depends on YouTube services, this issue makes development very difficult.

Strangely, I didn’t have this problem before. It only started in the last couple of days, even though I haven’t upgraded Chromium or web-ext. Maybe Google recently changed its detection logic?

When I launch Chromium manually from the terminal with:
/usr/local/bin/chromium
everything works fine — login, search, YouTube playback.

So my final question is:
👉 What is the actual difference between launching Chromium directly (/usr/local/bin/chromium) and launching it via web-ext run --target chromium --chromium-binary "/usr/local/bin/chromium"?

How can we fix it ?