Try the following:
Turn off Steam Cloud for Titan Quest Anniversary Edition
This concerns people playing on: Steam, GoG, Microsoft Store, Epic Games
Between each of the steps, try to run the game and check if your bug is fixed
Steps
🇦 Restart the store client and make sure you're connected to the internet. (Steam, GoG, Epic Games)
🇧 Run TQ.exe in admin mode.
🇨 Verify files with the store client you're using (e.g. Steam)
🇩 Restart computer
🇪 Update the graphics card (GPU) drivers
🇫 Update Windows
🇬 Reinstall the game and delete all folders and files related to TQ. (make backups of your save files first).
🇭 Reinstall Microsoft .NET Framework (see guide on internet)
🇮 Reinstall Visual C++ Redistributable (see guide on internet)