I'm having slight problems with the CM3+ module...
I've written the dts overlay and got SCL1 and SDA1 working fine.
The pins 28 and 29 should be SDA0 and SCL0 respectively, which is confirmed when I type raspi-gpio get 28,29.
So it should be set. But whenever I type i2cdetect 2, 2 because it's detected under /dev/i2c-2, it just goes slow, probably timing out on the pin detects. It goes much slower than i2cdetect 1.
I'll provide additional info if needed.
UPDATE: The BCM numbers for above GPIO numbers are:
GPIO-28 - B12
GPIO-29 - B1
