Kodi audio issues

[Fester Bestertester]

Hi all.
My 3B was coping quite well with Kodi freshly installed. I'd been trying to use VLC, but both audio and video were severely chopped up. mpv Player played audio smoothly, but video again was choppy. Websites had Kodi as a second choice, so "Why not?" JOYsomeness!
until for some reason no audio - and no volume control! I've noted a red icon at top-right, speaker and x, but can find no explanation or means of restoration to proper function. Apt-get remove, purge and (re-)install made no difference. H E L P !!
p.s. I'm running the Pi at a rest home, into their VEON 20" TV, (via HDMI but old enough that its media player barfs on mkv files).

[LTolledo]

been using Kodi 18.2 on RPi3B, but its still on Raspbian Stretch (can plug the Buster USB later, installed with Kodi 18.4)

now watching video on it (a 720p video, while typing this post). No video lag, no video choppiness,
no audio lag (HDMI, or analog, even bluetooth...)

same thing I expect with my RPiZW Kodi Media Player and RPiB (c. 2012) Kodi Media Player
no choppiness, no lags.. so it plays fine

Ok just tested my RPi3B with the Raspbian Buster containing Kodi 18.4
as expected, plays fine
no lags, no choppiness,

have you set the gpu memory to at least 196MB?

to go further... 1080p/8bit, 720p/10bit, ok, plays fine no choppiness, no lags (audio/video)

however choppy video/audio on 1080p HVEC 10bit videos (due to buffering, which is expected on the RPi3B)

playing the same 1080p HVEC 10bit video on the RPi4B-4B plays smoothly......no lags, no choppiness...