SwOS 2.12 on a CRS305-1G-4S+ breaks SFP-GE-T copper modules that still work on a CRS317

After upgrading a CRS305-1G-4S+ to SwOS 2.12, SFP-GE-T 1000BASE-T copper SFPs stopped linking although the switch still identified them in the SFP tab; the same modules kept working on a CRS317-1G-16S+ with the same firmware. Modules inserted before the upgrade continued to work, modules inserted afterwards did not.

• Hardware: MikroTik CRS305-1G-4S+, MikroTik CRS317-1G-16S+
• Transceivers: SFP-GE-T 1000BASE-T copper SFP, no-name 1G RJ45 SFP
• Form factor: SFP

Symptoms / messages:

module identified but no link after firmware upgrade