Are you using the newest version? I thought I fixed this little bug of the browser. Have you tried different devices to see if they all have the issue? Because I don't have this using zpix.
Viewing post in Opentype Pixel Font Renderer for MV/MZ comments
For sure! Appreciate you taking a look. I think what I figured out is that, at my 320x180 game resolution and 1x font scale, the bug appears. But on a new project with the font at 2x scale, the bug is not there. Anywho, here's a link to my project: https://cilerba.com/fontbug.zip
Got it. You can edit line 646 of the plugin, change 17 to something bigger for example 18, should fix your problem.
for (let i = 0; i < 18; i++) { //dummy commands, fix gpu glitch
This problem should also be gone if you upgrade nw.js to the newest version. Seems to be a glitch of the browser when drawing very small shapes.