Mbed Studio Debugging LPC4088 "no Ack received"

I am trying to debug an LPC4088 board and am receiving this error message:

0005479:ERROR:gdbserver:Unhandled exception in handle_message: No ACK received

when i run:

pyocd list --targets

I receive a list of targets, among them:

lpc4088                   NXP                     LPC4088                                 builtin
lpc4088dm                 NXP                     LPC4088dm                               builtin
lpc4088qsb                NXP                     LPC4088qsb                              builtin

So I had assumed this would work. Should this be working? Is it possible to make it work somehow?