Extract function removes some unicode

Hi all,

We are on 17.1 cloud installation. I observed one behavior with Exact function. I am not sure whether it's as designed. Following is the detail.

Text string: This is a text with & and some other stuff

Function implementation: extract(
"This is a text with & and some other stuff",
"with",
"some"
)

It returns result as, "& and" instead of "& and".

Is that expected?

Thanks!