Why bonding link is flapping which is resulting in specific logs on switch side ?

Issue

• Bonding on this server flaps with the following messages seen in switch logs.

Sep 14 13:48:28.714 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 9c8e.991c.xxxx
in vlan 1 is flapping between port Po20 and port Gi0/24
Sep 14 13:48:43.923 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 9c8e.991c.xxxx
in vlan 1 is flapping between port Po20 and port Gi0/24
Sep 14 13:48:59.157 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 9c8e.991c.xxxx
in vlan 1 is flapping between port Po20 and port Gi0/24
Sep 14 13:49:14.374 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 9c8e.991c.xxxx
in vlan 1 is flapping between port Po20 and port Gi0/24
Sep 14 13:49:15.683 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 001c.c4c1.yyyy
in vlan 1 is flapping between port Po20 and port Gi0/44
Sep 14 13:49:29.608 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 9c8e.991c.xxxx
in vlan 1 is flapping between port Gi0/24 and port Po20
Sep 14 13:49:40.991 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 001c.c4c1.yyyy
in vlan 1 is flapping between port Po20 and port Gi0/44
Sep 14 13:49:44.833 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 9c8e.991c.xxxx
in vlan 1 is flapping between port Po20 and port Gi0/24
Sep 14 13:50:00.058 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 9c8e.991c.xxxx
in vlan 1 is flapping between port Po20 and port Gi0/24
Sep 14 13:50:12.843 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 001c.c4c1.yyyy

• Why the links are flapping ?