refunds are likely to trigger that but other things trigger it too.
If no drops happen for you for hours, then you are flagged for possible abuse and no drops in any game will happen until 3(three) hours of playtime are passed, after that everything as normal.
this is also a very safe method for testing the following more quickly You can trigger the first drop after 4-5 minutes of playtime by submitting your playtime, that means exiting the game. The drop timer can be set differently for each product, default is 30 minutes, only the playtime Steam knows matters, there are some products where the droptimer is 3 hours, no joke.
