LED blinks on Picostation

Alternating LEDs (1 and 3 of the signal strength alternating with 2 and 4)
PL1234
xxx_x_
xx_x_x
xxx_x_

Ubiquiti's documentation says this is caused by about any sort of hardware failure, that does seem to be the case. Sometimes it is the CAT5 cable's fault. Sometimes the POE injector, etc.

Flashing Signal LEDs (1 - 4 of the signal flash)
PL1234
xx____
xxxxxx
xx____

With the latest AirOS, this seems to indicate that the SSID matches but the security key does not. Interestingly, this does not seem to apply to the older PicoStations (Picostation HPs with version 3 or 4 AirOS). Not sure if that is a hardware model change or a firmware change.

All LEDs flash on and off (all 6 LEDs flash simultaneously)
xxxxxx
______
xxxxxx
I only saw this once. The picostation was working intermittently. I did a site survey and found out that there were 22 APs on the same channel!!! Switched channel and LEDs returned to normal.

Link LED blinks

The <-> seems to only flash when it is trying to grab a DHCP IP address. It does not seem to indicate activity ever. Is that correct? Does this LED indicate link to a POE or Ethernet? Did that ever change (seems like it has)