MA302 Input Pin Voltage 5V vs 3.3V SPI

Currently using the MA302 and connecting to the SPI interface with an Arduino nano.
Although the datasheet says that the input pins are 5V tolerant (which they are!). The device doesn’t seem to consistently read or write to registers when the input pins (MOSI, SS/CS, CLK) are 5V. Installing a simple resistor divider to step down just MOSI to 3.3V fixed the issue. Leaving CLK and SS at 5V seems to work fine.
Is this expected behaviour? Im guessing you probably only guarantee it to work at 3.3V but perhaps some details in the datasheet explaining this could be helpful!
My final implementation using this sensor will be with a 3.3V microcontroller so I’m not concerned, but took me a while to figure out what the issue was.

EDIT: Just noticed that the datasheet does actually say up to 5.5V on the input will register as a HIGH. Unsure why this wasn’t working for me then. It would occasionally read/write fine but the majority of the time it would just return the angle instead of the register contents. 100% consistent running input pins at 3.3V though

Hi Will,
Thank you for utilizing the MPS Technical Forum,

The input pins being 5V tolerant refers to the I/Os ability to accept 5V. Also, that the minimum “high” voltage exceeds the TTL/CMOS threshold.

There is a possibility that this issue might be due to the controller not being able to meet the TTL/CMOS logic threshold standards. If the issue persists with using 5V, we recommend using a level shifter along with your project. If you ever so choose to go from 3.3V back to 5V for the communication pins.

Kind Regards,