Customer reported 2 of their ports connecting to different devices is flapping intermittently

Customer reported that two of their interfaces, which are part of different LAGs and connected to separate devices, are flapping intermittently.

We could observe below logs during interface flapping

Dec 19 13:17:40 labroot lacpd[23581]: %DAEMON-5-LACP_INTF_MUX_STATE_CHANGED: ae106: xe-5/1/4: Lacp state changed from COLLECTING_DISTRIBUTING to ATTACHED, actor port state : |-|-|-|-|IN_SYNC|AGG|SHORT|ACT|, partner port state : |EXP|DEF|-|-|OUT_OF_SYNC|AGG|SHORT|ACT|

Dec 19 13:17:40 labroot lacpd[23581]: %DAEMON-5-LACP_INTF_MUX_STATE_CHANGED: ae105: xe-5/1/5: Lacp state changed from COLLECTING_DISTRIBUTING to ATTACHED, actor port state : |-|-|-|-|IN_SYNC|AGG|SHORT|ACT|, partner port state : |EXP|DEF|-|-|OUT_OF_SYNC|AGG|SHORT|ACT|

Dec 29 23:42:57 labroot lacpd[23581]: %DAEMON-5-LACP_INTF_MUX_STATE_CHANGED: ae105: xe-5/1/5: Lacp state changed from COLLECTING_DISTRIBUTING to ATTACHED, actor port state : |-|-|-|-|IN_SYNC|AGG|SHORT|ACT|, partner port state : |EXP|DEF|-|-|OUT_OF_SYNC|AGG|SHORT|ACT|

Dec 29 23:42:57 labroot lacpd[23581]: %DAEMON-5-LACP_INTF_MUX_STATE_CHANGED: ae106: xe-5/1/4: Lacp state changed from COLLECTING_DISTRIBUTING to ATTACHED, actor port state : |-|-|-|-|IN_SYNC|AGG|SHORT|ACT|, partner port state : |EXP|DEF|-|-|OUT_OF_SYNC|AGG|SHORT|ACT|

After analyzing the extensive interface outputs for these two interfaces, it was observed that the ports did not experience any flapping during the reported issue time. These log messages indicate that the remote end of the link is going out of sync, suggesting that the issue lies with the remote port rather than the local port. The customer has been advised to investigate the peer device and replace the SFP on the remote end.