Question about TP-Link TL-WA1201

I bought the TP-Link TL-WA1201 to use it as an access point. However, I now find that of the channels 36-165 @ 5GHz only the first 4 (36-48) can be selected in the setup. Even on Auto it always goes to 36. On 2.4GHz the whole band can be used. If this is the case, the WA1201 is unusable for me, as the first channels are often already "full".