Serverless Warm Up Plugin Claims to have pre warmed functions when it has not

I am using the serverless warmup plugin and when I deploy my service I do not get any errors, and in the output the plugin claims to have pre warmed my functions. When I look in cloud watch I can see they have not been invoked and when I manually invoke I can see from the first invocation request time vs consecutive requests that it is not warm.

The output looks like this:

Serverless: WarmUp: Pre-warming up your functions
Serverless: WarmUp: Functions successfully pre-warmed

I actually think I know why this is happening, its because I do not have a route to the internet from inside my VPC:

  "errorMessage": "2020-07-13T10:24:24.036Z 4bc25cd2-1ff0-4271-a779-0b4dbf0191fa Task timed out after 20.02 seconds"

I can fix this (my traffic is only going on premise through a transit gateway) and I guess the plugin has no real way of knowing whether or not it really did warm the lambda.

A further problem I have is that there is no interface endpoint for the lambda service and I need to send any internet bound traffic via a specific proxy.

After all of this, I realised I dont even need to launch this lambda into the VPC at all and it will get internet access by default and all it needs is access to the lambda service to invoke the functions.

Due to this is doesnt have any access to my VPC (and so on premise) so I think this is actually the more secure solution.