I have added GA to a website by using GTM ID. Everything is working fine, I can see active users on the website, events which I have created etc. The problem is when I create a new view with a custom dimension filter.
In this case if I go to Real-time -> Events it is working, I can see filtered events but I always see 0 active users on the website.
Real time report is not reliable, try to check in effettive report if the data has been acquired.