MSP432E411Y: Reset Cause from RESC Register Says EXT but RST Pin Doesn't Go Low Enough

We are seeing the MSP432E411Y reset with RESC register value 0x00001, indicating the EXT bit in RESC is set.  The TRM (SLAU723A) table 4-17 indicates that this is caused by RST assertion.  However, probing the RST line with a scope probe doesn't seem to show that it should be getting triggered.\

Are there other causes of the EXT bit in RESC getting set than the RST pin going low (< .35*VDD) for 250ns or longer?

Thanks!