Man, proxies can be such a pain. One thing that got me: if you're on Windows, your system proxy settings might override your python requests proxy config.
Run this to check:
```python
import os
print(os.environ.get('HTTP_PROXY'))
```
If it prints something, your env vars are messing with it.
Run this to check:
```python
import os
print(os.environ.get('HTTP_PROXY'))
```
If it prints something, your env vars are messing with it.