title: Wrong Dates when Downloading Data in Loop through investpy
body: <p>I'm trying to debug some strange behaviour in some code I was using to download data through the investpy API (investing.com).</p>
  <p>What happens is that I initially downloaded data from 2000 onwards but changed the start date to 2007 to avoid NaNs. I'm running the data through a for loop for all the series I'd like to download. For some reason doing that doesn't change the start date and I do not understand why.</p>
  <p>To avoid misunderstandings: My question is not about how to cut-off the missing observations, that's easy. I'm trying to understand what causes this as I want to avoid another bug that I might be missing.</p>
  <p>Thanks for the help!</p>
  <p>Code:</p>
  <pre><code>import investpy
  import pandas as pd
  maturities=['3M','6M','1Y','2Y','3Y','4Y','5Y','6Y','7Y','8Y','9Y','Germany 10-Year','20Y','30Y']
  eu = list()
  for x in maturities:
      search_result = investpy.search_quotes(text=x, products=['bonds'],
                                         countries=['germany'], n_results=1)
      historical_data = search_result.retrieve_historical_data(from_date='04/01/2007', to_date='23/07/2021')
      eu.append(historical_data.Close)
  eu=pd.concat(eu, axis=1)
  eu.columns=maturities
  eu=eu.reindex(date).fillna(method='ffill')
  eu=eu.add_prefix('eu_')
  eu = eu.rename(columns={'eu_Germany 10-Year': 'eu_10Y'})
  eu
  </code></pre>