grammar - What is the difference between 〜ないではいられない and 〜ずに はいられない

I was taught that these two phrases are interchangeable and have the same meaning.

However, I recently wrote a few practice sentences using this grammar point and they were corrected to use ずには instead of ないでは

The sentences I wrote were:

1. 知り合いにそっくりだったので、話しかけないではいられなかった。


2. まだ子供なので、許さないではいられなかった。

However, both of these were corrected to:

1. 知り合いにそっくりだったので、話しかけずにはいられなかった。


2. まだ子供なので、許さずにはいられなかった。

I was under the impression that both were acceptable and can't find anything stating otherwise. Is there something in particular with these sentences that they can only use ずには？ Or am I completely missing something?