I'm having the odd problem where a STM32F4 wont resume operation after pulling NRST low. Power cycling the STM32F4 works just fine.
NRST is configured with a 0.1uF cap to ground. It has no other connections. On removing the jumper from NRST to ground, voltage on the NRST pin is 3.3V (as it should be).
Any ideas as to what may be causing this issue?