all my clients that authenticate using user manager realtime usage jumps around
It will be 2.1Gb now and 5min later 2.7Gb and a few minutes later 2.0Gb again

What can be the problem

Is it RouterOS/userman version 5.6?
Could you post screenshot describing your problem?

Yes it is RouterOS 5.6

All of these are taken 30seconds after each other.
I have set my interim update every 1min, and 1 session per host

Look at Willem, Sean Usage, and it even goes down to 2Gib each sometimes
User manager router does not restart or lose power at all

I have got another question, If lets say I set my transfer limit for my clients to 3GiB, and the client uses 2.5GiB Download and 500m upload, will my client get capped?

I have got another question, If lets say I set my transfer limit for my clients to 3GiB, and the client uses 2.5GiB Download and 500m upload, will my client get capped?

Yes.

Yes, it is very weird, that traffic is jumping. Perhaps User page could not display traffic correctly. Do you have any transfer limit configured for user?

I have configured the transfer limit on the profile and assigned a profile to the clients that has a transfer limit of 3GiB

What can be the problem with the usage that jumps around

When I click on a user and look at statistics, it does the same thing.

This jumping around cause my clients to get more bandwith for free I dont know how to stop this

Same problem here! New Usermanager really sucks, in my case even after 1 hour of mikrotik uptime, all "time left" records just disappears! What's wrong with this?

i think maybe before you use version 5.x better testing it first, otherwise back to 4.17.
about wrong usage, that possible just wrong count on userman? or may actually user get true transfer limit value 3g in fact, have you tested by yourself?.

Dear siprox,
We all know your advise! In my case i need sstp and i must use v.5.x, All i want is to mikrotik make usermanager ok! I had no problem with 4.17 or even earlier versions, New usermanager is bug full, slow interim updates, slow GUI, faulty active users sync and more and more, We deserve to mikrotik attention to this issue