Had a recent issue where a Google Chrome extension I built wasn’t installing via group policy. After a lot of troubleshooting I found an entry in HKLM\Software\Policies\Google\Chrome\ExtensionInstallSources. Once I deleted that entire registry key (not just the value), the and restarted Chrome, the extension installed using the pushed settings that is in HKLM\Software\Policies\Google\Chrome\ExtensionInstallSources.