I've been on vacation for the last week, and just got back last night. DX5 II was waiting for me on my return, and I set it up briefly last night, and spent a bit more time with it this morning.
On initial power on, it was detected fine by macOS and the VU meter showed an input source, but nothing came out of any input. Power cycling it resolved that issue and I've not seen it since.
I've updated the firmware to 1.39, but I'm still seeing the issue that after a power cycle all PEQ configuration set in Topping Tune is lost. The memory location created stays, but everything in that memory, its name and all EQ values are missing. Did anyone find a workaround for this yet?
Oh, and no import duties requested yet!