Person Biking

Neither — the plain one leaves gender open. The man and woman riders exist for when that detail matters; otherwise the bare character works as a general cycling sign, even for a group when the context makes that clear.

If it looks male on an older phone, that is old artwork: before platforms moved to neutral default drawings in the late 2010s, most vendors drew plain 🚴 as a man. The character itself never changed, so the same message may simply look different on an older device.

It came from phone emoji and a European transport proposal

In January 2009, Unicode proposed encoding the emoji held in separate Japanese mobile-carrier sets so they would display across systems. In April 2009, standards bodies from Ireland and Germany proposed a bicyclist and a mountain bicyclist — filed under transport and map symbols, not under their sports symbols.