from the tut https://www.scirra.com/tutorials/236/us ... ect/page-1
there may be a workaround for you;
Loading time for web fonts
A problem with web fonts is since they are downloaded, there may be a second or so delay before the font is ready to be used. Meanwhile the browser will either display a different font, or nothing at all. This can make the text appear to momentarily flicker.
The good news is the font is cached so next time it should load almost instantly - there's only a delay the first time the font is downloaded.
However, you can work around this by loading all web fonts on startup. For each web font you use in a project, add a text object to your first layout and use the Set web font action to load it. Make the text hidden so it's never seen - it's just loading the web font. Splash screens or title screens are ideal for this. If your splash or title screens use a web font, you might want to use an image there instead, or introduce a second or two delay to give the fonts a chance to load. Then, nobody should ever see the text before the fonts have loaded.
That's all there is to it - have fun using your fonts!
You may also be interested in the tutorial How to use your own web fonts by Przemek32767.