Can't get hotswap to work on Asus motherboard for SATA 5 & 6

Question

Recently bought an Asus PRIME B450-PLUS motherboard with 6 SATA connectors. I've got a couple of Akasa SATA hot-swap drives that I'm trying to get running on SATA 5 & 6. I've set the connections as HotSwap Enabled in the BIOS but hotswap is not working. Running journalctl -f while swapping drives shows no action. SATA connectors 3 & 4 work fine with these same drives with journalctl -f showing all the communications with the kernel but I'd prefer to get them on 5 & 6, if only for neatness. SATA connectors 5 & 6 are separated from 1-4 on the M/B, is there some jumper or BIOS setting I need to mess with?

Answer 1

Just got an email response from Asus support...

The M.2 Socket shares bandwidth with the SATA_5/6 ports, and therefore the SATA_5/6 ports cannot be used when an M.2 device is installed.

Which is bl*dy annoying as the reason I selected this M/B was in order to have 6 SATA ports and an M.2 device rather than fit a 2½" SSD drive. In fact it's even more annoying that the M.2 device takes out 2 SATA ports. Fortunately I only actually need 4 ports in this build with the M.2.