Render blocking scripts can cause this behavior. Honestly you need to debug your sites performance to determine what you can effect and change. There is not a tool that can automate this; only report. Google’s page speed insights is a good choice to start.
Re: blocked loading. Webflow is not doing the blocking; your browser is based on your policy settings. I have seen a drop of over 40% in traffic reporting on many sites I manage. Privacy is the thing.