I just recently ran into this issue which took me all day to figure out and it had nothing to do with the resource providers. With my Terraform script I included a variables file that included variables that were not needed (I copied code from a previous project). When it got to the plan stage it was waiting for the input for the variables. I was able to figure it out by including in my yaml file under the plan task.
commandOptions: '-input = false'
This will keep it from looking for the variables that are not used. Instead it threw an error, which once I removed them from the file it ran correctly.