Problem Extracting Text from Between Specified Text

Question

I am attempting to select text between specified text, as indicated athttps://www.extendoffice.com/documents/excel/5103-excel-extract-between-two-characters.html#a3

Unfortunately, following the instructions, the formula does not seem to work except if the text in question is at the very beginning of the string.

The formula provided by Kutools Formula Helper is:

=IFERROR(MID(I3,FIND("Format:",I3)+LEN("Format:"),FIND(",",I3)-FIND("Format:",I3)-LEN("Format:")), "")

And it is meant to select text between "Format:" and the next comma in the string. However unless the string begins with "Format:" it returns nothing.

So for instance it works fine with this string:

Format: book, Author: Tolkien

but it fails with this string:

Author: Tolkien, Format: Book