When using 2 BNO085s (one extension) the primary IMU errors after a few minutes

[Pyrofer]

Hardware assembled and tested with single tracker, and it works perfectly fine.
Without the extension the primary tracker works and does not give an error at all.
When a second BNO085 is added as extension, the primary tracker fails after 30s to a few minutes but the extension continues to work.
The error happens alongside a large variation in positional data from the IMU, seemingly a 180flip taking it upside down and then an error.
This flip seems to happen with a single primary IMU but doesn't cause the unrecoverable error after, a simple full reset gets things back to normal and it doesn't happen again, only once shortly after powering on the tracker.
When swapping the IMU address' for the Primary and secondary IMU the fault still happens on the primary, so may be connected to the int pin being used? Swapping to pin 7 instead of 5 didnt fix it.
changing the extension to a bmi160 with the exact same cable/setup elsewhere stopped the primary from crashing.
The issue only haplens with 2 bno085 clone boards and is not cable/hardware/soldering related.

The BNO085 in question is the clone Ali version with purple PCB and identifies as the following,
SW Version Major:0x03
SW Version Minor:0x02
SW Part Number: 0x98a64b
SW Build Number: 0x06
SW Version Patch: 0x0d