Please tell me that you are a genius

Hi!

Im looking for days to find a solution – please tell me that i found it:

I run a multisite with subdomain set up ( mainsite: mysite.com and subsites xy.mysite.com)

I already have a lot of registered users – they all can register and login form the mainsite (mysite.com) and also can publish posts from the frontend. Now i created a subsite (xy.mysite.com) and will provide all users the same infos about her profile as in the mainpage. So far all users are listed in the network user list and mainsite userlist (backend)…

The Problem – the users are logged in when they visit my subsite (xy.mainpage.com) but can not upload images ?? and they are not in the backend user list of the new subsite!

I already find this plugin: www.ads-software.com-plugins-multisite-user-management

But i dont like Plugins they are not updated for months and eventually die ??

1.So please tell me – that your plugin is the magic im looking for? Does your plugin copy all user profile informations and other stuff to the subsite?

2. Does it do all automatically if a user just visits the new site if he logged in from the mainpage – because i let users only log in on my mainpage.

3. For example – i let the users also log in from the subsite (xy.mysite.com) and then tehy visit the mainsite – does it work also this way??? (so i can eventually let users log in on all sites?)

4. if you answer the q above with yes – please tell me, that you are a healthy guy who will live long and update this plugin for the next years? ??

5. I found this article – https://wpquestions.com/question/showChrono/id/8226

what you think about this solution in the functions php?

best