EdgeRouter 4 logs Failed to read SFP EEPROM_1 at byte 0 val -11 with a Bell Huawei MA5671A GPON stick

An EdgeRouter 4 (EdgeOS 1.10.0) with the GPON SFP taken from a Bell Home Hub 3000 (Huawei MA5671A, SC connector, DDM readable: 50.9 C, 3.25 V, 8.87 mA, TX 1.36 mW, RX 0.02 mW) logged kernel: Failed to read SFP EEPROM_1 at byte 0 val -11!! twelve times a minute although the internet worked. Removing hardware offload did not change it; after a shutdown and reseat the module briefly reported no vendor/part data at all and the errors stopped, then returned about two hours later once the module warmed up. An ER-6P user saw the same messages together with eth5 link down/up events.

• Hardware: Ubiquiti EdgeRouter 4, Ubiquiti EdgeRouter 6P
• Transceivers: Huawei MA5671A GPON ONU SFP (Bell), Cisco SFP
• Form factor: SFP

Symptoms / messages:

Failed to read SFP EEPROM_1 at byte 0 val -11!!
Failed to read SFP EEPROM_1 at byte 109 val -11!!
eth5: Link down / 1000 Mbps Full duplex cycling