Upfront and default widget style

Still on our trial membership evaluating the system. Noticing some very strange behaviour using Upfront Builder and the Fixer theme.

Add default wordpress widget categories to the blog page ie menu, recent posts etc etc.

Load Upfront, edit the default widget styling to make headings larger, change the font weight and colour. Save fine. Go back into the site or change the page, closing upfront. Go back to section changed at a later date and none of the changes made to the blog widget settings have saved. Check the CSS and they show but do not show live - its as if they have reverted back to the default.

Is Upfront broken or is this a know issue - seems to make editing using the Upfront builder questionable if settings do not remain active on save? Also, have noted several issues whereby content block added goes grey ie a widget. Only reverting back clears the issue.

Concerned this is not working properly. Thanks.