terraform-aws-autoscaling VS terraform-aws-rds

So in the root dir I have created a main.tf that is sourcing git::https://github.com/terraform-aws-modules/terraform-aws-autoscaling.git

In this example TF mofule I am looking at, https://github.com/terraform-aws-modules/terraform-aws-rds/blob/master/examples/complete-postgres/main.tf

Hello there, I created an RDS from a snapshot using the following module: https://github.com/terraform-aws-modules/terraform-aws-rds nowadays when I change the value of snapshot_identifier to null, Terraform tries to force a replacement of RDS. The creation from snapshot was one-time activity (We do it when we have to recover data or rollback to the previous version) and I want to keep the code idempotent now. How can I make sure that any future runs do not terminate the existing RDS to create a ‏‏‎ new one? Thanks. ​ Edit - Title of post could be misleading, so apologies for that.

Hi all, i am using the rds aws module and i am trying to import a db_parameter_group. its giving me hard time because it wants to switch the parameters to null. as you can see in my screenshot, in the state the proper values exist, and i dont understand why it wants to turn them into null. the submodule responsible for that is db_parameter_group and i dont know how to fix it, can anyone help me please? (i guess something needs to be changed locally in this part of code? )

The db module in our service is using aws rds module. Even Idownload this module to local, add lifecycle ignore in its db_option_group module resource, how to avoid these 2 services' changing?