Issue with page level interactions - formula help

In that case, simply add just the logins count measure to the filter on the matrix table.

Login count measure:

Logins = CALCULATE(COUNT(User_Login[UserID]), FILTER(User_Login, [Action] = "Login"))

Login measure on the matrix filter list and set to is not blank:

And a date selected on the graph that is filtering the matrix to just those users that had a login on that day:

Just to make sure I understanding correctly, you want a DISTINCT user count?

If you create a measure using the distinct count on the UserID column on the User_Login table you can actually put the AppVersion and count of users in a matrix and not require any further actions to filter.

Count of Users = CALCULATE(DISTINCTCOUNT(User_Login[UserID]), FILTER(User_Login, [Action] = "Login"))

Let me know if that answers the question.