Running a prototype changes font weight!

Hi,
we had this issue in 3 separate prototypes at my company recently. The prototypes are running fine unless viewed in Incognito Mode or during live tests with users (super professional).

At certain inconsistent points the message ‘missing fonts replaced’ will show up and then the prototype breaks. This can be something benign like a regular font weight instead of bold, but it will also fail to render text entirely (the autolayout compensates, so the text literally isn’t there).

We noticed that this issue could be reproduced when we triggered some visibility changes via toggles. Repeating hide/show (as in filtering a list and toggling a boolean on certain elements) will eventually cause the issue. Sometimes immediately, sometimes after a few iterations.

As the fonts get loaded correctly initially, we assume that loading in custom fonts during runtime of the prototype is causing issues. Does Figma forget things when elements are hidden and tries to recover from faulty caching, is it a network issue when trying to reload custom fonts, does showing previously hidden objects re-render these differently than during the initial load? - we don’t know.

For now, we replaced all fonts with a Google font and the problem seems to be resolved. I couldn’t reproduce the bugs anymore, but this is NOT a solution. We can’t be testing UIs with some Google font just to appease Figma, not to speak of the man-hours we sank into fixing this.

This has been happening to my prototypes as well - same issue as everyone else has described. Notice it’s been 3 months since the last message, so assuming there’s been no fix…? 

Hi everyone, I want to start by apologising for not giving an update on this thread!

I’ve checked in with the team, and they confirmed a fix for this issue was shipped about 3 months ago. That said, if you’re still running into font weight changes when running a prototype, the team really like to take a closer look. The best way for us to investigate is if you can share a file link and invite support-share@figma.com with “can edit” permissions (this won’t affect your billing), or send over a quick screen recording.

This will give the team the details they need to dig in and help get things resolved.

Thank you, 
Gayani