S6812-48X6C 一组M-lAG的下联聚合口down

华三的两台S6812设备做的M-lag ，下联的思科设备做端口聚合，思科是RSTP

华三配置的默认stp。下联聚合口down，请问有可能是什么原因导致的呢？

出现了以下告警：

LAGG/6/LAGG_INACTIVE_OPERSTATE: Member port XGE1/0/34 of aggregation group BAGG34 changed to the inactive state, because the peer port did not have the Synchronization flag.

IFNET/5/LINK_UPDOWN: Line protocol state on the interface Ten-GigabitEthernet1/0/34 changed to down.

M-LAG/6/MLAG_IFEVT_MLAGIF_NOSELECTED: Local M-LAG interface Bridge-Aggregation34 in M-LAG group 34 does not have Selected member ports because the aggregate interface went down. Please check the aggregate link status.

STP/6/STP_NOTIFIED_TC: Instance 0's port Bridge-Aggregation34 was notified a topology change.

LAGG/6/LAGG_ACTIVE: Member port XGE1/0/34 of aggregation group BAGG34 changed to the active state.

IFNET/5/LINK_UPDOWN: Line protocol state on the interface Ten-GigabitEthernet1/0/34 changed to up.

M-LAG/6/MLAG_IFEVT_MLAGIF_SELECTED: Local M-LAG interface Bridge-Aggregation34 in M-LAG group 34 has Selected member ports.

 STP/6/STP_NOTIFIED_TC: Instance 0's port Bridge-Aggregation34 was notified a topology change.