Day Trading Buying Power stuck at $0 (live account only)

Environment

Python 3.9.1
Alpaca SDK Version
alpaca-trade-api 0.51.0

Problem

Summary
When I call the API to get the day trading buying power for my account it returns $0. The rest of the data returned by the api.get_account() call are correct. E.g. it correctly reports the equity in my account.

Paper or Live Trading?
This is only with my live account. It works correctly with paper trading. I just funded my live account at the end of last week, and this is the first time I’ve traded in it. When paper trading I set the starting balance to the same amount that I funded the live account with, and I meet the PDT rule requirements.

Example Code
api.get_account().daytrading_buying_power

I have the exact same issue!!! been troubleshooting it for days. Thought it was something wrong with my code. Turns out my day trading power is zero for some reason!!! PLEASE HELP!!

I checked this morning and the pattern_day_trader attribute on my account object is now True instead of False, and daytrading_buying_power has a value. The difference is that yesterday I made trades that would have triggered the PDT rule. So perhaps you have to be flagged as a pattern day trader before daytrading_buying_power is populated?