This is covered in the FAQ:
What about Lab caches?
Lab caches aren't considered as normal Geocaches by the system and therefore they aren't included in most statistics.
We do however include their count in the find count of the Profile Stats header. With time they will be included in several of the Profile Stats modules as well.
From 2017-11-21 (News), the lab caches are in statistics, but only for the paying members (feel free to check my stats -- the labs are there)/