Limit on logged users in meeting?

Hi, I have a strange issue... I have got a running Compilance Recording Bot based on sample bot (PolicyRecordingBot). It works like a charm, but, when we have a meeting, only 4 logged users (in our teenant) can join the meeting, anybody else (logged in our teenant) can't join the meeting with error saying that: "There was a problem setting up the recording required by your org. Try joining again.".
They can join only as guests to this meeting.
They also don't have problem in starting second meeting...
Can this be fault of the bot? But it only get notifications on joining users... it doesn't control it...
Policy? Didn't see any limits or settings on user count in meetings...
Can anybody point me in the right direction? What can be the issue here?

Start by reproducing the tenant meeting with the Compliance Recording Bot based on the PolicyRecordingBot sample, noting the four-user limit and the recording setup error. Review the bot's join notifications alongside the organization's recording policy and meeting user limits; done would be identifying whether the bot or tenant policy causes the restriction and documenting the confirmed remedy.