Since you talk about using LACP I assume the two Huawei switches are stacked. If this is the case then make a connection to each switch so that if one switch fails a connection to the other will still exist. The Huawei switches must be running spanning-tree, and one of the ports on the Huawei stack will get put into blocking state - the MX doesn’t participate in spanning-tree, it just forwards BPDUs. Hope this helps.