I forgot to say that I’ve added these queries :
And then, it works well with MAX(m1), MIN(m1), FIRST(m1), and maybe others.
But it did not work with PERIOD(m1) or TIME_SERIES(m1), and maybe others.
I don’t understand why the error message said the function is not supported, while this is proposed in autocompletion, and someone (oh it’s you 
) make it works(The AWS Cloudwatch PERIOD function (in expression) 5x smaller in 24hrs time range - #6 by jangaraj)