Did I read right? Do you powering hAP ax3 from RB4011 over passive PoE? I have two RB4011 with original power supply but none of them reboots. One of them is powering a hAP ax2 but thats all. Sometimes the grid voltage drops under 200V over here where 230V is nominal but RB4011 doesn’t rebooting. hAP ax2 is only 3W plus in typical, but 11W plus in peak. If your RB4011 drives a hAP ax3, try to power ax3 from different power source.
My hAP ax3 is powered via original DC adapter. I also tried another one with the same parameters but problem persists.
I think it is not related to power supply because it started after upgrade…and this is why I used this topic - I performed upgrade and I also use SMB.
I just wanted to say that you can have them connected at the same time. No discussion which one or if both are used at the same time however as we wrote voltage/current differences, power loops etc. could cause problems so replacing it with one good PSU for test should let dispel doubts.