Solved!
After loading Firefox on a third machine, which rendered correctly, I went through all the settings to see if anything was different on the rogue machine. I found Options/Content/Fonts and Colours was set to Times New Roman 20, whereas the other machines were set to Times New Roman 16. Changing this setting has fixed the problem.
Not even within the browser?I am running the lappy at the recommended res of 1920x1080 with no other scaling.
Yes, I run Chrome on all my devices and it's only the lappy that does it.Could you run the same browser (and version) on your laptop as you do on your desktop? If you can, does this solve the problem?
Tried that. It was set to 100%, but I have swapped that around to no avail.(I think) 150% scaling somewhere.
No. Just tried altering the zoom in Chrome and it makes no difference. Also, I can zoom around on my desktop and Surface Pro and its solid OK. It's OK on my Android tablet as well.Not even within the browser?
Ah Ha. That was the problem. (been running down the investigations and unfortunately left yours to last).I found Options/Content/Fonts and Colours was set to Times New Roman 20, whereas the other machines were set to Times New Roman 16.