Dataset extracting issue in ADF - status code 400 Bad Request

Hi everyone,

I built a pipeline in Azure data factory to download bright space datasets in batches.
Some of the datasets extracting gave me HTTP 400 Bad request error.
What confused me is some of the datasets extracts worked, some didn't.

The download link URL is like this:

I have noticed that when the extract ID are numbers, the pipeline works fine. I am able to download these datasets. Example:

When the extract ID contains letters, the process always fails. Example:

The error message is:
"Http request failed with client error, status code 400 BadRequest, please check your activity settings."

I couldn't figure out how to solve this. It makes no sense because if the url is problematic, the whole pipeline should fail. But it wasn't the case.

Did anyone experience the same?
Any help is appreciated.

BTW, what is the meaning/difference between extract IDs that consist numbers or letters? (Just try to understand the logic )