On Friday (01-Feb_2019), I went to Tarman’s Berth and managed to knock out Tarman, but before I could put bindings on him, he fell through the ground and disappeared on me. I also killed a dancer and was able to harvest/loot the body with no problem.
It was just north of the land bridge between Tarman’s Berth and Lookout Point.
Yes, I am actually getting this issue here and there on testlive as well. In Asagarth and in sepermeru. Fortunately for me, I was just knocking out random thralls, not t4 ones.