A dynamic font size of 112 is huge and will take a long time to generate glyphs for new characters on mobile.
On top of that, you're continuously changing the DynamicFont size and adding font overrides, which may cause Godot to render dozens of font sizes you'll never see. Look into fixing that first.
If that still doesn't solve the issue, you need to either pre-render the font on startup by displaying all ASCII characters for one frame in a label then hiding this label, or use smaller font size but scale the Control up using the rect_scale property (which will look blurry).
Note that setting rect_scale in a Container won't work if you do it in the editor – you have to do it at run-time using a script, with an one-frame delay if it's done in _ready():
set_deferred("rect_scale", Vector2.ONE * 2)
