Information

Full output of /ess version:

16.11 18:45:47 [Server] INFO Server version: 1.13.2-R0.1-SNAPSHOT git-Paper-428 (MC: 1.13.2)
16.11 18:45:47 [Server] INFO EssentialsX version: 2.15.0.45
16.11 18:45:47 [Server] INFO LuckPerms version: 4.3.17
16.11 18:45:47 [Server] INFO Vault version: 1.6.1
16.11 18:45:47 [Server] INFO EssentialsXSpawn version: 2.15.0.45

https://gist.github.com/Tomographix/d0b9972ea9921a33829c5269cb9a5d45

Details

Description
Users placing spawners in 1.13 who are no OP turn into pig spawners.
OP users have no issues placing spawners of any type.
Users do have the permissions to place spawners including:
essentials.spawnerconvert.*
essentials.spawnerconvert

Steps to reproduce

1. Summon a spawner: e.g. give {name} mob_spawner:99 1 name:&7&lIron_Golem_Spawner
2. Place spawner
3. Spawner is a pig

Expected behavior

1. Summon a spawner: e.g. give {name} mob_spawner:99 1 name:&7&lIron_Golem_Spawner
2. Place spawner
3. Spawner is an iron golem one

Tested without EssentialsX on, the spawner still turns into a pig.
Tested with latest experimental builds, spawner now places correctly! Thank you for fixing.

Can you replicate this behaviour without EssentialsX installed?

In addition, can you try using the experimental builds?