I just setup my brand new asiair+ (firmware updated) and had a similar issue.
From power down I inserted a brand new sandisk 32gb sdcard (FAT32).
Powered up asiair+ and sdcard was not recognized, removed sdcard with asiair still powered up and inserted into computer which saw ASIAIR as named device with 5 empty folders.
Removed from PC and reinserted the sdcard while asiair+ was still powered on and sdcard was immediately recognized.
After asiair+ reboot and power down/up tests the SD card is always recognized.