Tasha's Hideous laughter intermittently non-functional

[goate]

I'm playing a human bard.  Every once in  a while I'll cast Tasha's Hideous Laughter on someone or something, and nothing happens.  No check, no flashing animation that I've noticed showing that they have spell immunity.  Nothing.  The screenshot below is from June 1st 2019.  Either  Godfrey de Valencourt or Sigismund Zekaelym were the target (I can't remember which one).  Both are human race.  The target was hostiled.

As you can see, absolutely nothing seems to happen when Tasha's is cast.

The spell works as normal most of the time.

[Grouch]

What are you trying to cast it on?

[goate]

PCs, in the screenshot above.  I've had it fail when used against NPCs as well.

[Tala]

Were the PCs hostile? I think it won't trigger against nonhostile.

For NPCs, it won't work on mindless creatures like Constructs, Undead, etc.