Font size slider is unresponsive

Ref. 2579

From Darkstar on Telegram:
https://t.me/CodeOnTheGoDiscussions/1183
Unable to change font size.

<img width="623" height="1280" alt="Image" src="https://github.com/user-attachments/assets/a8cd2990-31b6-48e2-9d5b-f3bc06c045c7" />