On Ubiquiti's PtMP access points, there are limits on what the maximum amount of clients are that can be connected at once.
Ubiquiti's hard limits on airMAX M and airMAX AC are as follows:
AC with GPS Sync enabled: 60
However, even though these are the hard limits, to achieve the best performance it is recommend to evaluate how well each device is connected and this is determined the channel width, signal, and noise.
If you run into any issues, send an email to firstname.lastname@example.org or contact us via live chat.