I honestly doubt it, both based on RSSI from a client and actual real power being emitted.
I'm not sure if you manually picked channel 36 or it did. But, Tx power, channel selection, and channel width have a weird and often fluid relationship between them though. It might see DFS activity and limit your power or change your channel, or both, but also the things it's looking out for are often frequency hopping by design and intermittent in nature. So things it's asking your router to do tonight might not be present tomorrow.
If you're going to manually pick a channel, it just might not accept the Tx power and/or the channel width you select because of other RF stuff it sees and you don't. Different things happen any way you slice it, but I think if you really wanted to insure you were, using the widest possible channels, for example, you'd want to have channel selection on auto.
5ghz is relatively new to consumer WiFi, and it's a nice chunk of spectrum (5180-5825mhz! in the US vs 2412-2484 on 2.4ghz) but a big part of why Wi-Fi got it was automatic, unavoidable, (yet dynamic and relatively seamless) interoperability with nearby other transmitters (mostly weather radar and aviation use radar [which may actually be weather radar also, I can't tell if it's used for planes or clouds]). Different channels have different regulations in different parts of the world, and even if a channel is under DFS regulation, for example, that doesn't mean it is automatically imposed upon your router.
http://www.summitdata.com/blog/?p=752
http://en.wikipedia.org/wiki/List_of_WLAN_channels
http://www.wi-fi.org/knowledge-center/glossary/8
http://www.cisco.com/en/US/prod/col...aecd801c4a88_ps5279_Products_White_Paper.html