Is there any resultant entry in update.log from either attempt? If so please post it. Maybe it's not responding to HWID folder 1651 again.

It has defaulted into preboot because the data in region 14 cannot be read. The firmware (main system software) in there is responsible for initiating the bootloader in region 5 and that isn't happening therefore the situation is the same as 'System Software Missing' on splash screen. The data in 14 appears not corrupt or missing as evidenced by the earlier dump of it which compares the same as a heathy fw_all.bin from O6x0 fw:
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The first difference is the numerous FFs behind the checksum 2B in your dumped 14.bin and those empty FFs merely represent the unused space in the device's region (a dump "rrgn" copies the entire region, i.e. data and unused space).

So what we can tell from that is even though the proper fw data is there in 14, something is preventing it from being used by the device to boot itself properly. Not only that, even though we were previously able to write new data to 14 it's not allowing that now using the same method we used before.