Let’s try clearing the Battle.net App Cache and see if that helps you here!
Press windows key + R > Type %programdata% > Click OK > Delete the Battle.net and Blizzard Entertainment folders
Press windows key + R > Type %appdata% > Click OK > Delete the Battle.net folder
Press windows key + R > Type %localappdata% > Click OK > Delete the battle.net and Blizzard Entertainment folders
After this don’t forget to right click and run the Battle.net App as Administrator.
If the issue persists, please upload your system files to pastebin.com and reply with the links to the files using the preformatted text option to encapsulate the links.