[MC-134540] The entity data of spawner get lost when player far away from it

The bug

I placed a drowned spawner with drowned spawn egg and command,then I changed the data of drowned made the spawner spawn a drowned with a trident by using "data" command. But when I far away from the spawner and return, the data of spawner got lost and it spawn normal drowned.

How to reproduce

Place a spawner
```
/setblock ~ ~ ~ spawner
```
Right click this spawner with a drowned spawn egg
Use this command to change the spawned drowned by this spawner
```
/data merge block x y z {SpawnData:{HandItems:[{id:"trident",Count:1},{}]}}
```
→ It will spawn drowned holding a trident
Move far away from this spawner
Go back to the spawner
→ It will spawn empty-handed drowned, not drowned holding a trident

Note: it won't happene if I use this command directly:

/setblock ~ ~ ~ spawner{SpawnData:{id:"drowned",HandItems:[{id:"trident",Count:1},{}]}}