nRF Kconfig GUI not saving changes

Question

Hi, 
 I have an issue with nRF Kconfig GUI in VS Code. 
 My prj.conf is empty, and the _defconfig file of my board contains this:

# Enable UART driver
CONFIG_SERIAL=y

When I open the GUI and search for serial, it indicates that it is turned on, which is correct as it's enabled by default. If I untick it, it shows up in the "changed" tab. However, if I click "Save to file" and select my prj.conf , and error message appears, saying " No changes to save. " 
 
 My VS Code: 
 Version: 1.99.0
Commit: 4437686ffebaf200fa4a6e6e67f735f3edf24ada
Date: 2025-04-02T21:35:19.530Z
Electron: 34.3.2
ElectronBuildId: 11161073
Chromium: 132.0.6834.210
Node.js: 20.18.3
V8: 13.2.152.41-electron.0
OS: Darwin arm64 23.2.0 
 
 Extension: 
 Installation
Identifier
nordic-semiconductor.nrf-connect-extension-pack
Version
2025.4.4
Last Updated
2025-04-11, 10:32:13 
 
 Using the latest SDK.