/back location not registering after /spawn

[jakematt123]

Nucleus Version

3.0.0-BETA7

Sponge Version

SpongeForge 1.16.5-36.2.5-8.1.0-RC1153

Java Version

Java 11

Plugins/Mods

Nucleus, Luckperms

Describe the bug

When a player does /spawn, their /back location is either incorrectly stored or not stored at all. I have tested /back with the warp command and it works just fine. However /spawn causes you to lose your last location. /back does not cause any error exceptions, the command runs how it normally would.