I think that 800v3 upgraded v4 with 'just' the HDMI card may not pass audio over HDMI but only through the SPDIF outs. This may mean that other v4 functionality is also not available even if cards are installed.

Chris

Lounge/Cinema, Trinnov, DSP8000XE, 4x 320.2 in-ceiling, M6 rear, 2x DSW.2
Roon Nucleus+ and 320.2 in-ceiling in many rooms (KEF in-ceiling in bathrooms)
Spare: DSP5000, 598, 562v2, 500Mk2, 518, 519, 504, 101B, M3, 861v4, 800 DVD, MS600, MC200