I am using an InfoPath 2013 form published to SharePoint online. The form is published fine, looks great, functions great, etc. and opens in SPO as a browser form (we do not want to install the InfoPath client for users). The form opens fine and all fields seem to function fine, except the date picker fields. They initially default to today's date, so they may rarely need to be changed, but in the web browser form clicking the calendar icon to change the date gives a bunch of gibberish symbols - see pictures.
I've tried opening the web form in Edge, IE and chrome, and all give the same result when clicking the date picker calendar icon
Expected result should be a typical SharePoint dropdown for date selection