Am I correct to assume, that an Echo Knight can’t use Manifest Echo, to create an echo on the inside of a spherical Wall of Force?

Here once more a classical Wall of Force blender question. I understand that spells can’t go through a spherical wall of force because of full cover, but does the same actually apply to class features like the echo knights: Manifest Echo?

You can use a bonus action to magically manifest an echo of yourself in an unoccupied space you can see within 15 feet of you.

If this is by RAW possible, I see that a DM would probably rule it differently I just want to know if there is an actual rule preventing this, also for the purposes of an Echo Knight potentially escapeing a Wall of Force or simmilar prison effects.