Ligo has detected a rather unusual black hole merger, where one was 20 solar masses, the other was thirty, also their axis were not aligned, meaning these could have been primordial black holes
https://www.ligo.caltech.edu/news/ligo20170601
https://www.scientificamerican.com/article/ligos-latest-black-hole-merger-confirms-einstein-challenges-astrophysics1/