Should a device that supports WPA2-AES be able to connect to a Mixed Mode network (WPA-TKIP, WPA2-AES)?

Question

I'm not sure if this is the right place to ask this question, please let me know if it is not.

I have a specific question about the 802.11 security standards for WiFi.

I am using an embedded WiFi bridge device that supports the following modes: "WPA-TKIP, WPA-TKIP+AES, WPA2-AES".

When configured for WPA2-AES mode, it can connect to an AP that is set for WPA2-AES only. However, if the AP advertises mixed mode (support for both WPA-TKIP and WPA2-AES), the device will not connect.

Is there a requirement hidden somewhere in the 802.11 standards that say a device should support these mixed-mode setups?

The datasheet for the part does not answer this question and I'm having a hard time with the 802.11 specification document itself.

My understanding is that a mixed-mode (TKIP & AES) AP will mean that a client that wants to use AES will be forced to use TKIP for group/multicast communications and AES for pairwise communicaitons.

Thanks for the help!