Security settings can sometimes cause peculiar behavior when accessing some webpages that are not "trusted" by your computer.
In order to avoid this behavior, you might need to add TaxACT's website to your list of "Trusted Websites". You should add both https://www.taxact.com and https://www.taxactonline.com to your list of Trusted Sites.
The instructions below use Internet Explorer as an example. For specific instructions for your browser, you may wish to review the "Help" section provided within that browser.