Audio/ Video no synch Mimolive

At launch of the live everything is fine, audio and video are in sync but the delay gets bigger and bigger the longer the show is. Yesterday for exemple at the end of 3 hours live we ended up with close to a second delay on the audio.
Equipment :
-Mac Pro 2020
-Catalina

  • A SONNET Box, ECHO EXPRES SE III
  • Decklink 8K Pro
  • Decklink Quard HDMI Recorder
  • Decklink mini monitor 4K
    The setup had 2 Panasonic robot camera AWUE70K, the sound came from a sound console ONYX producer 2.2.