hi,
we had a similar issue... but in our case with a "C9300-NM-2Q" module inserted in C9300-48UXM with Version 16.12.04.
suddenly both 40GE ports went down (but port wasn't in error-disable state)
374122: Jul 5 09:59:20.867: %LINEPROTO-5-UPDOWN: Line protocol on Interface FortyGigabitEthernet1/1/1, changed state to down
374123: Jul 5 09:59:20.874: %LINEPROTO-5-UPDOWN: Line protocol on Interface FortyGigabitEthernet1/1/2, changed state to down
374124: Jul 5 09:59:20.880: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel11, changed state to down
374125: Jul 5 09:59:21.874: %LINK-3-UPDOWN: Interface FortyGigabitEthernet1/1/1, changed state to down
374126: Jul 5 09:59:21.889: %LINK-3-UPDOWN: Interface Port-channel11, changed state to down
374127: Jul 5 09:59:21.890: %LINK-3-UPDOWN: Interface FortyGigabitEthernet1/1/2, changed state to down
shut / no shut didn't solve the issue but reload did it as well.
anyone else with similar issues and other solutions?
thank you
frank