"closed pipe" error on bledis command

I am trying to use the "bledis" command, and my PLT occasionally gives me this error message:

discover profile: can't discover services: ATT request failed: input channel closed: io: read/write on closed pipe

I am using the exact command from the test plan reference, i.e. "bledis %BLEMAC% 30 -60"

When the error occurs, it appears immediately. When it doesn't show up, the BLE discovery command works as expected.