The member intefaces of eth-trunk appeared that frequently up/down , but eth-trunk is up all the time, and MSTP topology changed all the time.
Set a fexed STP cost for eth-trunk
[HUAWEI] interface Eth-trunk 1
[HUAWEI- Eth-trunk 1] stp instance 2 cost 200
The member interfaces of eth-trunk's phenomenon of up/down would cause the cost of STP change, and then STP/MSTP would recalculate which caused topology changed.
We suggest to set a fixed STP cost for eth-trunk in the network with STP /MSTP.