(bluetooth) time delay in audio on fresh 9.97 installation

  • I've installed a fresh 9.97.1 (19.1.0) on my Raspberry Pi 4

    First of all it's wonderful that the mediathek from arte is working now, Thanks.

    But I have issues with sound. First I thought this is a bluetooth (PULSEAUDIO) problem, but same issue is with audio over hdmi (ALSA). Then I detected that it's not a problem with streams from the mediathek, only videos and live tv, which are served by Ultimo 4k OWIF 1.2.8 - VTi (14.0.6/2020-02-25-vti-master))

    There is a delay of around 1s which seems to increase the longer TV is runing. I've searched around and used a bluetooth dongle instead, but there is no sound at all. Stop/Start of TV is not the solution. Similar, but not that large delays are in videos. as mentioned, streams via mediathek seam to be ok.

    I've no idea where to start for solutions. It would be kind if you can support me with some hints (or a solution ;) )

    LOG with CSR4.0 Dongle and disabled in config.txt (dtoverlay=disable-bt), No sound and no possibility to select BT device: http://ix.io/3uN5

    LOG with onBoard bluetooth, but asynchron video/audio with ~1s: http://ix.io/3uN9

    EDIT: The system runs on a 4K monitor with 3840*2160 @30Hz

    Thanks for your attention.