You have 5 spaces in front of the array you are attempting to display as code.
After 4, it assumes that you were trying to write a code block, but that additional space confuses it possibly.
Removing one space "should" resolve the issue:
But you could also instead of using spaces backtick encapsulate it ( using ``` before the code line and after) to create a code block and then code doesn't need the 4 spaces in front any longer.
- Code blocks should be used for code. One reason is that code blocks are not indexed in site searches (Not applicable here, but important to know).
- The formatting applies to all exchange sites.
This information is available to the right of the post as you are creating it and additionally the information displayed under the question body points to the additional space possibly being an issue. Displaying exactly where would be nice (The first array in your question is the one with 5 spaces FYI), but it's the hint under the body section that led me to find the extra space.