Environment:
Operating System: Mac OSX 10.15.6
Firefox version: Firefox Nightly 103.0a1 (2022-06-16) (64-bit)

Preconditions:
ETP set to STRICT
VPN actively pointing toward the US
Clean profile
Account previously created

Steps to reproduce:

1. Navigate to: https://www.moneysupermarket.com/my-dashboard/
2. Perform account login via email or Google.
3. Hover or click on the drop-down menu options.
4. Observe the result.

Expected Behavior:
The options are opening.

Actual Behavior:
Nothing happens.

Notes:

• Not reproducible with ETP set to STANDARD.
• Works as expected using Chrome.
• Screenshot is attached.

It appears that they rely on Optimizely, but the version hosted at https://cdn.optimizely.com/public/8787468851/s/MSMGlobalWeb.js.

Adding *://cdn.optimizely.com/public/*.js to our list of URLs for the Optimizely shim in SmartBlock seems to do the trick here.

Depends on D150040

Depends on D150040

Comment on attachment 9282489 [details]
WIP: Bug 1774737 - add another URL to SmartBlock's list for Optimizely

Revision D150063 was moved to bug 1775048. Setting attachment 9282489 [details] to obsolete.

The candidate patch here landed as part of bug 1752990, and the page seems to work fine now for me in the latest nightly.

I managed to reproduce this issue on a 2022-06-17 Nightly build on macOS 10.15; verified as fixed on Firefox 103.0b7(build ID: 20220710185935) and Nightly 104.0a1(build ID: 20220710190527) on macOS 10.15.