Bug report: subsection operations has problems with double characters

**Describe the bug**

When using the subsection operation, different sections are extracted if double characters occur.

**To Reproduce**

**Recipe**
Fork('\\n','\\n',false)
Subsection('...(.)',false,false,false)
To_Upper_case('All')

**Input:**
zazaza
bbbbbb
abcdef
aafedd

https://gchq.github.io/CyberChef/#recipe=Fork('%5C%5Cn','%5C%5Cn',false)Subsection('...(.)',false,false,false)To_Upper_case('All')&input=emF6YXphCmJiYmJiYgphYmNkZWYKYWFmZWRk

**Expected behaviour**
There should be a capital letter in the same place in each line.

**Screenshots**

**Desktop (if relevant, please complete the following information):**
- OS: Windows 10 21H1
- Browser: Chrome Version 91.0.4472.114
- CyberChef version: Version 9.28.0

**Additional context**
Add any other context about the problem here.