Curling up of the stem on a clone

I cut the stems of some new cuttings and some of them have curled up like this. I have never seen this and I want to know if something is wrong. I am using an oxycloner which is a deep water cloner. This one has been in water for around a week. I used a brand new razor blade from a pack of 100 for box cutters to make the cut. There was a oil on the blade. I did not clean the blade before use. Im wondering if this is why it is happening. PH is 5.7

I don't know anything about cloning but it looks to me like the soft tissue inside might have swollen while the outside of the stem stays tough, thus causing the curl.

recut and start again