2 Cave Spider spawners changed to pigs inside and completely stopped spawning spiders. When changed version back to 1.8.9 spawners show no entity inside and spawn nothing. Worlds that I had not previously loaded a snapshot and was using 1.8.9 had spawners working correctly.
If I use the setblock commands to spawn in a spawner in creative it has only a pig inside and spawns pigs regardless of the entity id entered.
Not a launcher issue. Please choose the correct project at the top of your screen.