<t>Disabling this made it lightning quick.<br/>
<br/>
Try this to see if it is a particular extension.<br/>
<br/>
- Open Command Palette (Ctrl+Shift+P)<br/>
<br/>
- Type in "Disable all installed extensions"<br/>
<br/>
- Enable them one by one or in groups and test the<br/>
IntelliSense speed</t>