Power over ethernet settings for icx by default are going to send enough power to H550 and equivalent access points so that the access point can provide PoE out.

This will sometimes cause a switch to have insufficient power to bring up all the access points that are connected to it because the power budget was originally designed for a scenario where the access points have PoE out disabled. Use the following settings on the switch in order to turn down the power out and enable all access points to come up online in a mode where PoE out is disabled.

interface ethernet 1/1/2
inline power power-by-class 4

In some cases the following settings is required:

Inline power power-limit 15900