ProSafe Smart Switch GS724TPv2 port 25F won't stay connected to another GS724TPv2 port 25F

[atekcomputer]

I replaced two failed FS726TP switches with two new GS724TPv2 switches.  There's a fiber cable connecting the two switches, however, port 25F will not stay connected.

Looking at the Log, here's some output:

<181>1 2021-01-21T19:12:06.866Z 192.168.2.117-1 AAA-5-CONNECT login.c(152) %% New https connection for user admin, source 192.168.2.11 ACCEPTED

<182>1 2021-01-21T17:39:00.446Z 192.168.2.117-1 LLDP-6-NEIGHBOR_DEL proto_lldp.c(4754) %% Neighbor deleted on port GigabitEthernet25: Chassis ID 44:A5:6E:4D:16:6A, Port ID g26

<181>1 2021-01-21T17:39:00.826Z 192.168.2.117-1 TRAPMGR-5-PORT_LINK_DOWN ksi_snmp.c(230) %% Interface GigabitEthernet25 link down

<182>1 2021-01-21T17:37:52.106Z 192.168.2.117-1 LLDP-6-NEIGHBOR_DISCOVER proto_lldp.c(4950) %% New neighbor on port GigabitEthernet23: Chassis ID 50:9A:4C:13:77:FF, Port ID 50:9A:4C:13:77:FF

<182>1 2021-01-21T17:37:02.156Z 192.168.2.117-1 LLDP-6-NEIGHBOR_DISCOVER proto_lldp.c(4950) %% New neighbor on port GigabitEthernet25: Chassis ID 44:A5:6E:4D:16:6A, Port ID g26

<181>1 2021-01-21T17:37:01.836Z 192.168.2.117-1 TRAPMGR-5-PORT_LINK_UP ksi_snmp.c(232) %% Interface GigabitEthernet25 link up

Port 25F will reconnect after a few minutes, then go down. 

Any suggestions on how to fix this?

Thank you!

Jim

[schumaku]

Can you provide some insight on what this "fiber cable"  connection is made of?