PVA glue is honestly the main culprit here. It's water based so it gets pulled into the paper fibers really easily, almost like a sponge. That capillary action happens super fast with thin paper because there's just less material to absorb it. You might have better luck with a thicker paper weight, like maybe 32 lb instead of 20 lb. Switching to a glue like methyl cellulose, which dries clearer and is less wet, can sometimes help a lot too. The trick is using a super thin, even layer and letting it get tacky for a minute before you press the pages together.