Don't know why you would get 11 on that antenna. A small antenna should not get much VHF - wavelength is too long.
Attic installation? Performance of an attic installation is always difficult to predict. You won't like it, but I suggest that you disconnect your antenna in the attic and move it to the roof - at least temporarily, to test reception. I'd also suggest connecting the antenna directly to the TV, using a new commercially-made RG-6 cable.
Also, if you read the Amazon reviews, this antenna can have factory assembly issues that could affect performance. One poster removed the plastic riveted connections and replaced the rivets with screws and nuts from the hardware store.
This antenna looks like a copy of the Antennas Direct DB2. Might be helpful to read their documents.
https://www.antennasdirect.com/store/DB2-Antenna.html