Scientifically speaking, electronic sensitivity is not a thing… i.e. psychosomatic… a coping strategy to be able to explain conditions.
There is however the rare chance to be sensitive to some of the materials used in the SS models:
Get a good fit and learn about Apple Watch materials.
support.apple.com
Or just a different feeling of weight/movement/pressure on the arm.
Our mind is quite remarkable at filtering and highlighting ‚changes‘ in perception be it just a few grams of haptics on the wrist.
so you might just want to give it a few days until it feels normal.