A signature shrinks by 1/2 every time it is saved

[ZenithElevate]

Today, a user was testing, and they saw a very strange behavior: the signature shrunk every time it was loaded from the DB and saved back. They were using a Samsung S26 with Android 14 to initially create the signature, and thereafter it shrunk. But I am not able to reproduce this behavior when I test on the latest Firefox, end to end. Only that signature which they created shrunk. This is arguably the weirdest thing that I've seen over my career.
My implementation follows your recommendation to the letter: the JS assigns the signature to a hidden, then the URL prefix is stripped, and the Base64 is saved in the DB. The loading follows the opposite process, and this works fine for all of a few dozens signatures that I've created myself. The code can load and re-save them as many times as I want, and they never ever change. There is nothing in it that could even remotely know how to manipulate the image in such a fashion.
Any ideas?

[UziTech]

Do you account for high DPI?

[ZenithElevate]

Ah, I wasn's aware that was a thing. With that snippet, the canvas keeps growing slowly when the browser window is resized.

[UziTech]

If you have a minimal repo showing it growing I can try to help