Some Infinity items have two text layers, so for changing the font family, you need to change the font family of two layers.
For changing the font family, follow these steps:
1. Select the text and set the font family which you want for it from the character panel.
2. Press the shy button to see all layers of the item.
3. Find the "Text 01" layer and hide it by pressing the eye button.
4. Find the "_Text 01" layer and show it by pressing the eye button and remove the lock option of it by pressing the lock button.
5. Select it and set the same font family for it from the character panel.
6. Find the "_Text 01" layer again and hide it by pressing the eye button and set the lock option for it by pressing the lock button.
7. Find the "Text 01" layer again and show it by pressing the eye button.