External Effect Causing audio to peak/distort when monitoring channel

I have added an external hardware EQ. After I have recorded audio to a track, then activate the effect, the result is what I expect. However, If I want to monitor the track and and activate the effect, the audio peaks too quickly, distorting the audio. For example, listen my acoustic guitar, I want to play my acoustic guitar through my input, listen to the guitar while I play, and activate the EQ. It’s as though Cubase is doubling the audio signal when monitoring.