Shift+arrow not working as expected in blockquote

## Issue Overview
When using shift and arrow down in a blockquote, the caret moves to the citation instead of selecting the next.

## Steps to Reproduce (for bugs)
1. Put the caret in a blockquote.
2. Press shift+arrow down.
3. Observe the caret jumping to the citation.

## Expected Behavior
I expect multi-selection with the next block.

## Related Issues and/or PRs
#3038.
