ACF fieldroup with user registration in multisite with membership 2

Hi, I changed a single site to multisite. the subsites are an exact copy of the single one. In both I have ACF 5 with a fieldgroup with location rule 'show this fieldgroup' is equal to all or to register. In single site, when using the 'register' via Membership 2 plugin, the field group appears nicely under the normal registration fields, perfect. In multisite, the fieldgroup does not show up. How to make this happen in one of the 'blog' sites with MEMBERSHIP 2?