Try this setup, although I have BDP1 & BDA2, so may be different with BDP2
1/ convert file to aiff or wav, not flac.
2/ disconnect Lan ethernet connection on BDP and use buttons on front to choose track.
3/ disconnect spdif connection
4/ connect the BDP to the BDA using a cheap short <50cm generic usb cable. Also connect the AES connection
5/ Let the BDP fully boot before turning on the BDA, then choose the AES connection on the BDA only.
If this setup and method works for you, try a wifi usb dongle off Amazon for about £6 or $8 and plug it directly into the front of the BDP for control. Make sure the dongle has the correct chipset, for manic moose
Also try a demo of a Shunyata alpha digital mains cable on the BDP, if you can.