I am trying to use the TRIM function but it is not removing the space
I expect

A1 references to another field, and returns the value CT 1. I am
trying to remove the <space between T and 1. When I use the TRIM
function within cell A1 the value remains as CT 1. I have even checked
this with the LEN function and it returns 4.

The cell which A1 is referenced has a simple typed in value of CT 1,
the cell is formatted as General

What am I doing wrong?