Of course, asking for 32 or more digits of precision is a bit on the side of the ridiculous, when the numbers going into the computation are themselves only accurate to 4 significant digits. Even worse, numbers like this:
are not exactly the numbers you want them to be when converted to symbolic form.
That is, each of these numbers are stored as a double precision number, then converted into symbolic form. And that ratio is FIRST computed as a double precision number.
So you don't have exactly the numbers you think you have. Then asking for more digits is asking MATLAB to generate what are virtually garbage results.