Catalyst 9300 with C9300-NM-4G shows OEM 1000BASE-LX SFP but port stays notconnect

The poster set up several new Cisco Catalyst 9300 switches fitted with C9300-NM-4G network modules, configured GigabitEthernet1/1/1 as a trunk and enabled it, but could not get a link with any of several SFPs. 'show interfaces' reports 'GigabitEthernet1/1/1 is down, line protocol is down (notconnect)' with 'media type is 1000BaseLX SFP' and 6 interface resets. DOM output from 'show interface transceiver detail' looks healthy: Tx power -5.2 dBm, Rx power -4.7 dBm, all within thresholds. 'show idprom interface g1/1/1' identifies the module as vendor 'OEM', part number M-SFP-LX-C, 1000BASE-LX, 1310 nm single-mode, 10 km, DDM implemented. The captured text contains only the opening post; the twelve replies were not included.

• Hardware: Cisco Catalyst 9300, Cisco C9300-NM-4G network module
• Transceivers: OEM M-SFP-LX-C (1000BASE-LX, 1310 nm, 10 km), other unspecified 1G SFPs
• Form factor: SFP

Symptoms / messages:

GigabitEthernet1/1/1 is down, line protocol is down (notconnect)
media type is 1000BaseLX SFP
Tx -5.2 dBm / Rx -4.7 dBm within thresholds but no link
6 interface resets
Vendor Name: OEM in idprom