URLREAD not returning all data for YAHOO page?

I am trying to download the static webpage in Matlab using urlread and 9/10 times, the YAHOO page for the S&P 500 is not returned properly in Matlab?

s = urlread('https://finance.yahoo.com/quote/%5EGSPC/history?ltr=1');

For example, search for:

Aug 09, 2018

When I view the webpage in Google Chrome view source, it shows Aug 09, 2018 and the proper data, whereas the Matlab return jumps from Aug 10 to April 24?

What's weird is every blue moon, Matlab will return the complete webpage? I can't figure out what's happening? I've tried webread, increasing the timeout and still no luck? Why isn't Matlab returning the complete webpage?

Any ideas, Daulton