Hi Carlos!
It depends on plugins and how they handle the css insertion. The problem is that css generated by the plugin comes BEFORE the css from the theme in the and gets overriden.
There are several options for fixing this. First you can look into the plugin and see if there are option for altering that. You can also create a child theme that will not use the fonts in the theme (that will do with a small alteration in the “functions.php”.
You can also send me names of the plugins, I will look into them and see how can we circumvent that, so they will take priority.