I cannot get an Advanced Custom Field code snippet to work – and ACF support say it should work

You try to access to an ACF group of fields
group_5f7ee777725c8 and the function the_field need a field key (not the group key).

You shoud replace group_5f7ee777725c8 with the field key you’ll find inside the group. So in ACF menu click on the group group_5f7ee777725c8 and find the field key. It should start with field_XXXXX