As sbor says I would try an Internet browser better than Chrome (it's a crap) as Lightning, with advertising and tracking blocker included (you only have to activate them from Settings).
That said, keep in mind that free download servers often fail, especially in heavy files. I recommend, to download movies and series, on the phone with the Appflix application, obviously you should use it with WiFi connectivity.
The other option is to use Telegram and join download groups of series and movies, there are many. The connection from Telegram never fails because the files are hosted on Telegram servers directly.