While saving a file, the file gets broken

[progettoautomazione]

I have noticed a very annoying thing, not sure if you experience the same/you have a fix for this: whenever I save a file, if the file is like 3000-5000 rows it takes 3-4 seconds to save. Not big deal, I can wait. The big deal is that I noticed that in this timeframe, the file is corrupted. This means that if I use my application, while the saving is in progress, the application is broken. Example of the error I see in my app when I refresh the page while the file is saving: https://nimb.ws/TBlZIc
I used to adopt AWS Cloud9 as web-based IDE editor and this was not happening. I would say its kind of a big deal, so maybe there is an easy fix that I am not seeing. Any advice?
Thanks