J9283B SFP+ DAC not accepted in the front SFP slots of an HP 2920-48G: only the J9731A 10G module takes it

A 2920-48G-PoE+ (J9729A) rejected a J9283B 3 m SFP+ DAC with 00536 FFI: port 45 Transceiver type not supported in this port even though HP lists the cable as compatible; the same cable worked in a 2530 with SFP+ slots. Firmware had been updated without effect. A later reader noticed an old J9283B worked while a newer J9283B-61201 did not.

• Hardware: HP 2920-48G-PoE+ J9729A, HP J9731A 2-port 10GbE SFP+ module, HP 2530-24G-2SFP+
• Transceivers: HP J9283B DAC, HP J9281B DAC, HP J9285B DAC
• Form factor: SFP+, DAC

Symptoms / messages:

00536 FFI: port 45 Transceiver type not supported in this port