SugarCRM 7.7 visible if formula when checkbox is checked failing

I've just upgraded to SugarCRM 7.7.1.1.

In my Leads module I have a custom checkbox field.

When the checkbox is checked few other fields have to be visible. 

This was working fine in version 7.6.2.1

I'm using formula equal($is_onboarding_c,true)

After upgrade the fields are hidden even though the checkbox is checked (I can see it in web developer tool).

I tested using the formula with a field that is not a checkbox field e.g. equal($first_name,"Tolek") and it works correctly.

 

It looks like a bug.