Possible fix

[DanielAlves123]

isHologram() is returning false even when its hologram
you dont spawn hologram when creating new ArmorStandData object

[Shevchik]

Just creating armorstanddata object won't spawn hologram because you need metadata. isHologram checks if all needed meta is present. If it returns false then some meta is missing. I consider a marker meta a required meta, because otherwise nametag renders at different heights.

[DanielAlves123]

@Shevchik this check:
isOffsetSet(((Number) armorStandData).intValue(), Constants.DW_ARMORSTANDDATA_MARKER_OFFSET) returns false, it shouldnt
I suggest adding 1.25 to Y location