> I'm using the internal RC oscillator running at a nominal 8MHz

Brent, I'm convinced that there's something wrong with the
F88 IntRC at 8MHz. I've noticed problems with I2C (as I
documented in a thread to here and Microchip support) and
a couple of odd things that went away when I dropped to
4MHz or changed to 8MHz crystal

BTW, the query to MC support was not resolved

Unfortunately I'm snowed under with another job for a day
or two so can't help further, but try 4MHz and see what
happens

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