the light turning RED is not a warning – it just means more than 400 ma in that group of 4 ports. See the attached updated data sheet attached.
the RED led has no impact on the voltage applied – I am curious what might be going on… Can you test again and ignore the RED led – perhaps we have one or more defective ports????
we can send you our PoE tester to measure the actual current – the APs are likely far less than 15 watts,