Version: 1.30.0-insider (but also seen in released 1.29.0)
Commit: 24b0f75
Date: 2018-11-16T06:20:02.054Z
Electron: 2.0.12
Chrome: 61.0.3163.100
Node.js: 8.9.3
V8: 6.1.534.41
Architecture: x64

Steps to Reproduce:

1. Create a folder multiline-capture

2. Create a file test.md inside the folder with the following content:

   Use a loop to iterate over an array and
   print something.
   

3. Open the folder in vscode

4. Open Search panel, enable regex option and use: (array).+\n and $1

5. Hit return or Refresh. The preview in the search panel shows:

   a loop over an array and$1

6. Click on it to open the Replace Preview.
   It confirms that the match will be replaced by a literal $1

7. Close the Replace Preview. In this moment, the preview in the search panel changes to:

   a loop over an array andarray

8. Click on it again to open the full preview and see it confirmed that it will replace it by the capture group value array now.

9. Refresh the search. It goes back to $1

10. If you use Replace All, the result is as shown in the preview, so the match is either replaced by $1 or array depending on what it showed before you replaced all occurrences.

11. Remove \n from the expression and refresh search: The issue does not occur, the preview shows array as substitute value immediately.

Expected behavior:
I expect it to replace the match with the content of the capture group (which is array) all the time.

Does this issue occur when all extensions are disabled?: Yes