"User is not logged in" Error When Using Research Class for Yahoo Premium Access

**Describe the bug**
Authentication using the Research class in yahooquery[premium] is no longer working for me. Attempts to retrieve data now return 'User is not logged in', even though this was working as recently as last month.

**To Reproduce**

```
from yahooquery import Research

r = Research(username='enter_username', password='enter_password')
from yahooquery import Ticker
t = Ticker("AAPL", session=r.session, crumb=r.crumb)

tags = ['OperatingCashFlow', 'CapitalExpenditure', 'FreeCashFlow']
data = t.p_get_financial_data(tags, trailing=False)

print(data)
```

**Expected behavior**
Previously, the Research object successfully authenticated using my Yahoo Finance Premium credentials and allowed access to premium data via p_get_financial_data().

**Environment:**

I have an active Yahoo Finance Premium subscription

App password (not regular password) is being used

selenium is installed and configured

Package installed with: pip install yahooquery[premium]

This setup has worked consistently for the past year

**Additional context**
Authentication errors began occurring in early May 2025. I haven’t changed my environment or credentials. I suspect there may have been a change on Yahoo’s end that affects login or session handling.

Would appreciate guidance on whether a change in the login flow is now required, or if there's a known workaround.