When I enable jumbo frames on my Araknis switch while the AP-AC-Pro WAP is powered on everything works fine until power is disconnected from the WAP. Once powered back on the LED flashes blue and the WAP does not get an IP address.
I have to disable jumbo frames on my araknis, restart the wap then reenable jumbo frames on my araknis.
Could you try 4.0.9?
Devices > UAP > Config > Manage Device > Custom Upgrade
USG-4-PRO • USG
USW-48-500W • USW-24-POE-250W 2x • USW-16-POE-150W • USW-24 • USW-8-150W • USW-8
UAP XG • UAP-SHD • UAP-HD • UAP-NanoHD • UAP-AC-PRO 2x • UAP-AC-LITE • UAP-AC-IW • UAP-AC-M
UCK-G2 • UCK