When I issue seeks (only really noticed this on mobile, but likely occurs for desktop as well), with rating requirements often times I'm matched with players below the rating requirement.
eg. If I do a 1+0 seek for players between 2200-2900, I can match with players rated 2150 and so on.
eg. If I do a 1+0 seek for players between 2200-2900, I can match with players rated 2150 and so on.