I’ve gotten these too. But I have a reddish blonde beard and my tree trunk hairs are always solid black and like 7 grown into one. You can peel them apart and count how many follicles assimilated, lmao *Edit spelling. Dumb thumbs.
In subreddit r/mildlyinfuriating
In a post titled:
These annoying extra thick beard hairs that grow in my beard. Took a couple of days to find this one. Normal beard hair for scale