Hey Hannes, thank you for your response and sorry for the belated reply. I have made a post detailing my findings in the meantime.
This has happened only on two units so far but these are also the only two units that we have tested from the new batch. The Baros are also failing intermittently on our side and I suspect this also causes the internal SPI lines to fail. I am aware that ICs have performance tolerances but it is wild that these Cubes passed QC processes - they are not reliable.
So to confirm, you fixed the issue by opening up the Cubes and dropping in replacement ICs for the MS5611 Barometer? This is good to know but I will likely be forced to return my faulty units as we can’t amend our production process to fix broken parts 