I did several tests: Full Screen/Full Desktop mode, V-Sync/G-Sync on and off, I added the folder where the autosave files are stored to the Microsoft Defender exclusion rules, I updated the BIOS firmware, I updated the graphics card driver, I disabled unused audio devices, I disabled the Steam overlay and also I disabled the Steam Cloud storage for the game; after all of that I always got the same result: stutters every 5 minutes on the dot, which coincides with the autosave feature working (you can verify by looking at the last time the autosave files are updated).
If anyone has been able to fix or has found a workaround, I’ll be really grateful of a reply on this thread.