Describe the bug

https://apps.openei.org/IURDB/rate/view/5f73585d5457a3dc0b692d6f#3__Energy is a rate with mixed tiers, some with kWh and some with kWh/kW. SAM's URDB download code fails to pull the tiers for this rate

To Reproduce

Steps to reproduce the behavior:

1. Open a behind the meter model such as PVWatts-Commercial
2. Download the rate linked above
3. Max usage tiers do not match the URDB implementation

Expected behavior

Max usage tiers should match the URDB implementation

Additional context

Tested on 2023.12.17r2. I expect this would have worked circa 2021 based on previous projects, but haven't tested it.