Thanks!
I think I’ve figured it out - it’s a problem specific to our C++/MicroPython driver so didn’t show up on our tests as production test breakouts using big Raspberry Pis.
Turns out newer RV3028 chips have a different hardware identification number (0x44 instead of 0x33) so we’ll need to update the driver to accommodate this.
I created an issue here if you want to follow it: RV3028: `BreakoutRTC: breakout not found when initialising` · Issue #1135 · pimoroni/pimoroni-pico · GitHub
and some fixed builds here (just RP2040 boards at the moment):
rv3028: add new chip ID/version · pimoroni/pimoroni-pico@73bfb7f · GitHub