Summons despawn occasionally when going off the map

[Ted Lastname]

Steam or GOG

Steam

Single Player/Multiplayer

Single

Operating System

Windows 10

Terraria Version

1.4.2.1

Controls Used

Keyboard/Mouse

I've recently blown up my entire cavern layer, and when trying to clean up the off-map sections using nukes my summons will occasionally chase down something that spawned off-screen and then despawn. I haven't tried with other summons, but it definitely occurs with the Terraprisma.