Raspberry Pi 3 used to support 32 WiFi connections but is now limited to 10.  RPi 3 B+ and RPi 4 are now limited to ~4 [replacing Raspbian with Ubuntu 19.10.1 increases this to 32; what does Ubuntu 20.04 offer?]

Currently being discussed on xsce-devel mailing list...

Unlike in 2016, 32 simultaneous WiFi connections to RPi 3 (running the latest Raspbian Lite from 2018-04-18) no longer seem possible :/