Debricking Archer A7 vs C7

My understanding is that the Archer A7 is really a C7 that's been modified for Amazon's purposes. I have a C7v2 that I've reflashed several times. I've even bricked it a few times and recovered it with both the OpenWRT factory firmware as well as the original TP-Link firmware. So I'm familiar with the installation process.

I recently bought an A7 for my brother and it's now bricked. But none of the usual methods of debricking seem to work. If I replace this router, I'm finding another C7v2, but I thought I would reach out for help first.

I'm using tftp with a MacBook and I know how to detect the filename that the router is looking for. It says that it's finding the file: read request for ArcherC7v5_tp_recovery.bin: success

But then nothing. It's currently in a pingable state ( and I can also visit the web page for the reset mode, but that rejects uploading either the original TP-Link firmware or the OpenWRT factory firmware.

Any ideas? I'm embarrassed to add that I've bought two of these units (two brothers) and both are in this state. I did manage at some point to install OpenWRT on both of them, but for reasons that escape me decided to redo the process.