Tetra problem

[JTier93]

Is anyone able to identify what this is on my neon tetra?

Looks like it could be cotton wool disease but what is the weird white string in the middle?

Thanks in advance

 

[JTier93]

Another photo is this helps.

Any advice would be great!

 

[libertybelle]

Helpfully replying ‘I don’t know’ in the hopes someone else sees this. Could it be a physical injury?