I'm seeing a similar behavior in Chrome Only. On initial page load, the the legend div is improperly scaling, leaving only the title for the legend. This appears to be a chrome specific bug as I don't see this in Firefox or IE. I'm on the June 2017 release. The bug appears to have surfaced somewhere around the 3.2 release. If you use the browser's zoom out and zoom in functionality, it may temporarily resolve the issue. Otherwise you may just need to use a different browser until the issue is resolved.