MongoDB query becomes unexpectedly slow and broken

Hello Shane, Thanks for reaching out! Here is the result of index_information()

{'_id_': {'v': 2, 'key': [('_id', 1)]},
 'post_id_1': {'v': 2, 'key': [('post_id', 1)]},
 'user_id_1': {'v': 2, 'key': [('user_id', 1)]},
 'comments.reply_id_1': {'v': 2, 'key': [('comments.reply_id', 1)]},
 'comments.reply_publish_time_1': {'v': 2,
  'key': [('comments.reply_publish_time', 1)]},
 'comments.reply_user.user_id_1': {'v': 2,
  'key': [('comments.reply_user.user_id', 1)]},
 'scrape_time_1': {'v': 2, 'key': [('scrape_time', 1)]},
 'post_content_1': {'v': 2, 'key': [('post_content', 1)]},
 'ticker_1': {'v': 2, 'key': [('ticker', 1)]},
 'post_publish_time_1': {'v': 2, 'key': [('post_publish_time', 1)]}}

The index types for both post_publish_time and ticker are 1(asc)