Bug report: Forking breaks highlighting for regular expression and other operations

**Describe the bug**
On Chrome, Firefox and Edge it appears that when you apply fork, a subsequent regex doesn't perform match highlighting as per screenshots below

**To Reproduce**

Write simple input and apply regex looking for string 'test'. Highlighting is applied


Fork the same input and the highlight will disappear / not be applied


This also appears to break text highlights for selecting text


And forked:


**Expected behaviour**
Highlight of regex matches or selected text should occur regardless of fork operation being applied. I wonder if it relates to: https://github.com/gchq/CyberChef/issues/267

**Screenshots**
As above

**Desktop (if relevant, please complete the following information):**
* Version: 9.37.3
* Compile time: 14/04/2022 17:10:14 UTC
* User-Agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.41 Safari/537.36

Thank you!

Reproduce the issue by applying a regex and text selection before and after using fork in Chrome, Firefox, or Edge. Trace the fork operation and the highlighting behavior, then verify that regex matches and selected text remain highlighted after forking.

Written by the indexing model from the issue text.