MISO and MOSI are at low levels when the STM32G071RB SPI is idle, which is different from the SPI idle state of the STM32F429ZIT6U.

[DXinp.1]

G071 is different from F429. When F4 is idle, MOSI is high level and MISO is low level. However, when G0 is idle, MOSI and MISO are both low level, which seem to be incompatible with my external device

[TDK]

What external device?

The level of MOSI and MISO is a non-issue when the clock is idle. Not to mention that the device (either master or slave) is only driving one of those.

[DXinp.1]

The external device is DW1000 positioning module. F429 was used before, but now it is transplanted to G071, and there is a difference in SPI function. It is not clear whether the difference is caused by chip or program.

[TDK]

As indicated in the DW1000 datasheet, the level of MOSI only matters when there is a transition on SCK.

My guess if that your program doesn't work, and you noticed the MOSI/MISO lines are different and blamed it on that, which is nonsense. Stay objective.