Have you also turned on LLDP-MED?
EX-series switches use Link Layer Discovery Protocol (LLDP) and Link Layer Discovery
Protocol Media Endpoint Discovery (LLDP-MED) to learn and distribute device
information on network links. The information allows the switch to quickly identify
a variety of devices, resulting in a LAN that interoperates smoothly and efficiently.
LLDP-capable devices transmit information in Type Length Value (TLV) messages to
neighbor devices. Device information can include specifics, such as chassis and port
identification and system name and system capabilities. The TLVs leverage this
information from parameters that have already been configured in the JUNOS
software.
LLDP-MED goes one step further, exchanging IP-telephony messages between the
switch and the IP telephone. These TLV messages provide detailed information on
PoE policy. The PoE Management TLVs let the switch ports advertise the power level
and power priority needed. For example, the switch can compare the power needed
by an IP telephone running on a PoE interface with available resources. If the switch
cannot meet the resources required by the IP telephone, the switch could negotiate
with the telephone until a compromise on power is reached.
https://www.juniper.net/techpubs/en_US/junos9.3/topics/concept/802-1x-lldp-lldp-med-understanding.pdf
I hope this helps a little bit.