So a few people have been having trouble with spawners. When they've used a silk touch spawner, the spawner does not drop. Just warning to be careful, gather evidence if this happens to you, or break them in front of a mod. Be careful to double check what pickaxe you use as well. gummibear560 and skizzors44 have had this happen to them.
Yeah, be careful... However, it randomly appeared in my inventory a min or so after I mined it so idk what happened...
It seems to be dropping every time that I mine them now... I think it is just an issue when the TPS is low, because the TPS was 10 when it disappeared for me. And now that the TPS is at ~20 again, it's working fine... So, do not mine spawners while the TPS is low, there is a chance that you will not get the spawner back.