Audio Streaming in Network ?!?

Hello Dear Community,

I am new here and maybe someone here can help me with my problem and we can solve it.

I try to tell you the problem and maybe someone got help for me.

I bought several up2stream mini and connected them to sound speakers I get from my grandad.

They really works great to play music and now the problem get started. When I play music to them 1by1 from any source PC/smartphone via Bluetooth or Wifi (I think Upnp) there is no delay and it works really good. When I connect them to the 4Streamapp (2 or more speakres) to 1 group, there is a delay of about 3sec. Impossible for watch movies.

Then I tried something like VAC (https://vac.muzychenko.net/en/). There is like 0 delay (perfect for movies or etc) but they got a small but noticeable delay to each other.

Then I bought an audio transmitter (avanteree) who connect them via bluetooth, but the disconnect and bluetooth isnt the fine way of a sound system.

Now I am starting with an pi and installed home assistant, because I heared something about it to configure many things. I am struggeling with snapcast/hifiberry/volumio/pulseaudio and serveral things and dont know if these things can help me or manage the problem?

In total I am looking for a tool / app / hardware to got my little devices who works with DLNA / UPNP / bluetooth to stream audio from a video / movie with no or a minimum of delay.

Please help me