Hi @tomdodd4598, welcome to the forum!
This is super puzzling, it’s the first time I see this issue.
Can you please share more information about the device you’re using so that we can investigate this issue?
If you run python -m pip install strawberryfields instead of just pip install strawberryfields do you see any difference?
My recommendation in the meantime is to use Google Colab and use ! pip install strawberryfields (with the exclamation mark).
I look forward to seeing your reply!