The bug

Spawn eggs with custom entity tag for either item frame or glow item frame will summon the item frame in the ground when using it while looking at the top side of a block. In this case all item frames that aren't fixed will pop off immediately upon spawning in the block below.
For all other side of a block, horizontal or bottom side, the summoned item frames are offset correctly.

See video https://streamable.com/azj22t

Reproduction steps

1. Give yourself spawn egg with custom EntityTag for item frame or glow item frame

   /give @s minecraft:pig_spawn_egg{EntityTag:{id:"minecraft:item_frame",Facing:3b}}
   

2. Use spawn egg to summon item frame while facing downwards, looking at the top side of a block
   The item frame is summoned inside the block