Bugzilla

**Environment:**
Operating system: Mac OS X 10.15.7
Firefox version: Firefox 131.0

**Preconditions:**
Clean profile
ETP Strict

**Steps to reproduce:**
1.Navigate to: https://www.drupal.org/user/login
2. Observe the page


**Expected Behavior:**
The Captcha is loading as expected

**Actual Behavior:**
Captcha is not loading

**Notes:**
- Reproduces in ETP Strict Mode only
- Reproduces in Firefox Nightly, and Firefox Release
- Does not reproduce in Chrome

Created from https://github.com/webcompat/web-bugs/issues/142647

**Environment:**
Operating system: Mac OS X 10.15.7
Firefox version: Firefox 131.0

**Preconditions:**
Clean profile
ETP Strict

**Steps to reproduce:**

1. Go to Firefox browser and 
2. Browse to **about:config** 
3. Dismiss the warning 
4. Create a new preference item 
5. Type the name that stores the custom user  agent (general.useragent.override)
6. From the three choices select String and press +
7. You will see an input box where you can type: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/601.1.54 (KHTML, like Gecko) Version/9.0 Safari/601.1.54*
7. press Enter
8. Navigate to: https://www.drupal.org/user/login
9. Observe the page


**Expected Behavior:**
The Captcha is loading as expected

**Actual Behavior:**
Captcha is not loading

**Notes:**
- Reproduces in ETP Strict Mode only
- Reproduces in Firefox Nightly, and Firefox Release
- Does not reproduce in Chrome

Created from https://github.com/webcompat/web-bugs/issues/142647