World duplicates are seriously corrupted

I have a serious problem with duplicating worlds on PlayStation 5.

When i try to duplicate a world, one of two things happen. Most times there is an error message that say's: “Storage full, sour system is out of storage space. You'll need to delete some data before you can save anything".

Just to mention, all my worlds together are just about 1,9GB and my PS5 has still 93,82GB of its internal storage space free, so that can't be true.

The second thing that can happen, but doesn't very often, is that minecraft is creating the duplicate of the world, but a corrupted one. In this case the whole world gets ripped appart, chunks are cutted at random Y-levels or completely missing (screenshots), stuff that i have built is deleted, even the world generation gets weird. So chunks that were originally ocean are replaced with beach for exaple, or islands are generated were never one was, even new biomes replace the ones that were at the exact coordinate before creating the duplicate. It's like the world generation is trying to “overpaint" the world file at some spots.

In some very few cases the game kicked me out of the world instantly when loading such a corrupted duplicated world, showing me a message telling me: “disconnected due to world corruption"

I should say, that all the worlds i tried to copy, were old version worlds. Unfortunately i can't remember on wich versions i created them. The oldest one could be 4 or 5 years old, the newest one about 1½ years. I did not try this out on worlds, that were originally created on the latest version.

Due to all this, it's actually impossible for me to back up my worlds, something that feels a little bit risky, i mean, what, if the game corrupts the orininal files while saving them after playing on it? I would never be able to restore anything. Please help Mojang.

Edit: i forgot to say, that even the player data is deleted, so my whole inventory and levels aren't copied either.