RA6 won't erase

We've had a couple of R7FA6E10F2CFP that only seem to program once, and that's it.  We are using P&E programmers in our production, and no bits are changing in the chip configuration.  They will no longer erase.  I've tried downloading Renesas Flash Programmer, and tried using the J-Link to try to clear it up, but it just reports that the erase operation failed.  Is there a way to get them working again?  More importantly, what causes them to get this way?

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  • Here's part of the schematic, it's a custom board.  I think I'm stuck then, because P109 and P110 are used for SPI going to other hardware on the board and not brought out.  P201 is pulled high by a resistor and not brought out.  The USB pins are not connected to anything.  So, there is no way to restore it over SWD, it can only be done over USB or UART?  We've programmed hundreds of boards with no problem, not sure what happened to these two boards that only programmed once.  It's concerning that there is a possibility that boards could go out without being able to update in the field, we have a customized application that can do flash updates over CAN.  What could be causing the chip to get into this state?

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