The Roy Dennis Foundation has confirmed that the bird is from the IoW release and has travelled SW from the Wash over the last few days.

https://twitter.com/RoyDennisWF/status/1399460486673055752?s=20

A 2nd calendar year juvenile was seen over Walton Heath, Ham Wall RSPB at 1035 this morning, 31 May.  Being mobbed by carrion crow and lapwing.  Subsequently drifted off southwards.  No wing tags or other ID seen but assumed to be one of the wandering birds from the IoW introduction.