If you want your Twitch VODs and any Clips made after stream to be found in Search and Browse results for specific category, make sure the Category and Title edited appropriately after stream.
After stream, change the category of your VOD to the game you played that stream if you want it to be found in search results. Also any other clips made will be labeled that category and found in browse. If you played multiple games, change the category before each clip.
I cannot speak on any suspicions of the algorithm or how such changes effect it. However, from the one stream I tested, each change I made resulted in finding or not finding the VODs and clips.