Thanks for the suggestion.. I have already done this. The problem is that if I change the max size for the logo so that it appears at 100% zoom on the laptop, then it is much too big on the mobile view. If I leave the logo sizing to default ( nothing ) then it is fine on the mobile view but then needs 175% zoom to see it on the laptop. This is something relatively new.. When I 1st created the site some 3 years ago it was all OK. I think it has change within the last 4 months or so.
Thank you. I will contact WP support as suggested.
Thanks for that advice which seemed so hopeful.. I found the CSS code within the customize dashboard but there is no code that refers to site-logo as you have suggested above.
