Hi Hilary , seeing this issue on Windows 10 running Microsoft Edge as the browser. The SharePoint is running as part of our organisations Office 365 subscription. Sadly I don't have any options to test with other browsers.
I have seen further comments else where in the forum about updating CSS files , see https://www.infopathdev.com/forums/p/30636/119922.aspx#119922 but I am unclear where these CSS files are stored