Help APPS ADD COVERS ALMOST HALF SCREEN

[Calvados]

G3 went crazy this weekend.
Backed up all contents.
Factory reset
Reloaded all inf.
NOW I have an infuriating apps add taking up half my opening screen.
HOW please can I get rid of this?

 

[James L]

Don't install apps from places other than Google play. Or uninstall any apps you installed recently one by one to see which one is the offending app.

 

[glc]

Maybe you should not have "Reloaded all inf."

 

[Calvados]

Thank you all for replies.