Or is a "rate limit" set up in the EAP? This would limit the upload/download accordingly.

Before I can answer the question, I have a few questions:
Does the router also have a signal? Which router is being used? Is the signal (dBm) meant here at all? Or is this about the upload/download rates (Mbit/s)? Is the appropriate power supply being used for the EAP? Is the EAP configured correctly?