Bug report: Substitute producing invalid results with punctuation

[ryantheleach]

Describe the bug
When using substitution, cyberchef is unable to produce the following decrypted ciphertext.

.-_ should become, _.- but instead becomes _-_ and warns that the ciphertext and plaintext are different.

To Reproduce
Steps to reproduce the behaviour or a link to the recipe / input used to cause the bug:

https://gchq.github.io/CyberChef/#recipe=Substitute('.-_','_.-',true)&input=Li1f

Expected behaviour

I expect the output _.-

Screenshots