You'll need to find some way of troubleshooting the issue. Do you have access to a laptop with an ethernet or USB/Ethernet adapter? That will greatly speed the troubleshooting process since you can you move one powerline unit to various different outlets in your home and observe the results of a speedtest.
Some things to keep in mind...
- LED lighting can cause interference.
- Motor loads (like compressors, treadmills, etc.) can cause interference.
- GFCI outlets or circuit breakers can cause issues.
- AFCI outlets or circuit breakers can cause issues.
- Speeds are typically reduced when the endpoints are on different circuits.
- Speeds are typically reduced when the endpoints are on different legs/phases.
- Speeds are typically reduced when the wire length between the endpoints is too long.
You really need to plug both units into non-GFCI outlets on the same circuit in the same room with no other devices running on the circuit so that you can get a baseline expectation of maximum throughput.
In my home these units average about 80-100 mbps with a range of about 20-250 mbps depending on several factors. Surprisingly the newer Leviton GFCI outlets don't seem to have much impact on my speeds. However, running my treadmill can drop throughput from 120 mbps to 20 mbps instantly.
The fact that you're getting < 1 mbps is a bit unusual. Let us know what you find out.