Thanks for your time on this.
It is a screenshot of the site that the screenshot is on. The issue occurs on every page of the site, whenever that top menu is displayed.
I had tried deactivating plugins before resorting to posting here. Deactivating all the plugins makes no difference, it looks exactly the same with the same problem on every page of the site.
Same issue with Twenty Sixteen although the larger font display with 2016 doesn’t force the menu onto two lines, it just moves the site name and tagline up above the menu in Chrome while it is on the same line with FF.
I hadn’t tried Twenty Sixteen as I don’t really like that theme, but I had tried a few other themes and the problem was never really evident. I really do like the Twenty Seventeen theme though and the whole site was actually put together with that theme. Moving it to another theme means a lot of additional time restructuring a lot of the information unless I can find one with that same front page feature that scrolls through various sections.
Now I just rechecked on my Windows 10 computer. Looking closer it seems that the problem is really not replicated over there. I just had the Chrome window smaller than the FF window. There is an area when the viewing window is just a bit larger than the size where the tablet view kicks in where the menu begins displaying across two lines. I’ll just drop the menu down to less first tier entries to work around the issue for now.
Starting to look like it might be a browser issue on this computer, although I’ve never made any significant changes to Chrome here. I’ll try a reinstall at some point but I have a lot of other work I have to do on that site and some others. I spent most of yesterday wrestling around with this and don’t want to waste another day of my time or any more of your time.
Exasperating. Thanks again for your time but please don’t waste any more of it.