In the Settings, every browser has a setting to set your Home page.
If it won't set or stay set, run full scans with Malwarebytes and AdwCleaner:
https://www.malwarebytes.com/mwb-download/
http://www.bleepingcomputer.com/download/adwcle...
Remove any Add-on's, Extensions or other Search services in Browser settings.
I hope this helps. Feel free to ask back any questions and let us know how it goes. I will keep working with you until it's resolved.