Not at all surprising if you haven't changed anything.
You *did* verify this happens on all the ports of that chip?
I gave you all the clues I've got. You're the one with the
uniquely mis-behaving hardware...
Time for you to work harder at debugging your problem. You
have the hardware, the software source code, a cooperative
hardware engineer ... that's a lot more than most folk have
when they start to chase down problems like this.
- Dave
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