They rewrote the UI recently in their own toolkit, Floem [^1], and that broke all scaling under X11 for me (now the UI and fonts are rendered so large that it's unusable). It works fine in Wayland though...

Here's some issues that were filed for this same problem:

  - https://github.com/lapce/lapce/issues/2732
  - https://github.com/lapce/lapce/issues/2773
  - https://github.com/lapce/lapce/issues/2737

[^1]: https://github.com/lapce/floem