Could you please provide example what is the expected string you are trying to extract and how the extracted string from Test Studio looks like? How do you extract the string, are you using the recording or you are using coded approach
? You can try the coded scenario if you didn't, it may work for you as a workaround.
If you can provide us with access to the application and your test we can investigate further what will be the best approach to proceed.
Looking forward to hearing from you.