AFTV Gen 2 & TrueHD/AC3 - any way to force multi-channel audio?

I know there’s a firmware issue with the AFTV Gen2 affecting AC3 passthrough.

Is there any way to force AC3 or TrueHD to a multi-channel output, as with dts & dts-HD MA?

AFTV Gen 2, audio set to Dolby Digital Plus automatic
Plex Client 6.14.0.3665, downloaded using “Amazon Devices” link.
Side note: What’s the difference between “Amazon Devices” and “Amazon AppStore” downloads?

If I play a Blu-ray rip, H.264 video & dts 5.1 or dts-HD MA 5.1/7.1 audio, the AFTVg2 sends PCM 5.1 audio to my receiver.

If I play a Blu-ray rip, H.264 video & AC3 5.1 or TrueHD 5.1 audio, the AFTVg2 sends PCM 2.0 to my receiver. Passthrough = auto or disabled, makes no difference.

In all cases the on-screen display shows Direct Play.

Just wondering if there is a work-around until Amazon fixes their firmware.

Thanks.

AFTVg2 --> Denon 4300H --> LG 55B7P
PMS 1.11.3 on Synology DS918+