Providing that we are talking about fonts available through “import fonts” menu, does your browser support and do you have IndexedDB enabled in your browser (usually it is enabled by default):
https://html5test.com/index.html - search for “IndexedDB” string on this page and check if there’s “YES”.
Also, list of fonts imported can be displayed in Chrome if (after going to designer.io and putting at least 1 text field on stage) you press “F12”, go to “Application” tab, click “IndexedDB” on the left pane. Refresh the database by right click (or whatever else on Mac) and choosing “refresh”. Then go to “gravitFontsDB” database under IndexedDB tree menu. Then there should be imported fonts listed on the right.
Also, I just spotted that imported fonts aren’t listed at the front like previously, but all are ordered alphabetically, @lim.chunwui was this intended change? Shouldn’t imported fonts be at the front, ordered alphabetically, then webfonts?
If you don’t have any problems with the database or listing fonts due to browser settings, but the list just not update after adding/deleting, then we should file a ticket.