Why does Google say there was a suspicious sign in attempt on my account?
When you connect to Speedify, your internet traffic is routed through one of the Speedify's VPN servers. This means that your public IP address changes to the IP address of the Speedify Server to which you are connected.
If Google notices that you are connecting from a new location or IP address that has never seen you connect from, it will warn you about suspicious activity. If it's either mentioning your location or the location of a Speed Server you've recently been using, then you can safely ignore this issue.
You can read more about this warning at the link here: https://support.google.com/accounts/answer/1144110?hl=en&ref_topic=2401957