Can't type into Safari unless I open a second tab
Safari v12.1
Mojave 10.14.4
Mid 2014 21.5" iMac
Most of the time when I open Safari I can't type into a dialogue box. This happens when I open Google or any other website. If I then open a second tab everything works fine. If I go back to the first tab it still won't work. I can right click into a dialogue box and paste some text and search on it but whatever page opens I still can't type into a dialogue box.
I've cleared the Safari cache and most cookies but still no joy.
Any ideas folks?
iMac 21.5", macOS 10.14