Cannot save page settings Gantry 5

[david-mccreary]

Joomla 4.3.4
PHP 7.4.33
Gantry Framework 5.5.17
Hydrogen 5.5.17

Trying to add a GA4 code into head via page settings in Hydrogen for my default all pages style. Changes will not save. Popup appears, completely blank (see attached). I ran Fix Permissions in Admin Tools. No help. Google atom in Hydrogen appears to only support old UA- code. Any advice or help greatly appreciated. Thanks

[pablop76]

You don't have to use nuclear. Insert the code in Base Outline -> Page Setting -> Custom Content or Base Outline -> Page Setting -> Assets -> Javascript