I bought The Frame(2021) series TV just. Before i used MU7000 series TV and when i'm trying to watch Dolby Digital+ supported movies at internal apps (Netflix, Amazon Prime, USB Storage Devices) TV doesn't give to 5.1 Dolby Digital+ sound with harman/kardon AVR161S. My old television has the menu for set the sound format to Dolby Digital, Dolby Digital+, DTS. But The Frame doesn't have this options. When i'm trying to enter the same menu options is PCM, Auto and Pass-through, but pass-through is grayed. This option only activated at HDMI sources enabled. BTW i'm living at Turkey and when i'm contact with Samsung Turkey support they say "2020-2021 model years TVs doesn't have not supported Dolby Digital+ for internal apps". Does anyone have this problem?
The Auto function in Sound settings did a fantastic job before firmware 1901 and Dolby Digital was sent out fine in Internal apps but after the update including v1904, it is still broken and the TV outputs only LPCM in Auto mode and Passthrough not enabled in Internal apps. Samsung needs to fix both DD and DD+ support just like the Atmos support which was broken in 1901 and was fixed in 1904. They have yet to acknowledge this as an issue and currently lying instead of fixing the issue.
I have a samsung NeoQLED QE55QN91AAT and the same problem with 5.1 sound. When I play video directly from my home theater (DD +) everything works fine. When I do it via TV (audio played via HDMI (ARC)) the sound is STEREO. Before that, everything worked. I suspect that in my case the update v.1904 broke something. I only have PCM and Auto in the audio format options. "Samsung" please correct it as soon as possible.