The custom field (multi line text) having Wiki Style Renderer enabled is not displaying strikethrough text properly

Issue Summary

The multi-line text custom field with Wiki Style Renderer enabled displays the appropriate strikethrough text When the custom field is collapsed. If the field is compressed, the strikethrough text is changed to regular text.

This is reproducible on Data Center: Yes

Steps to Reproduce

1. Create a custom field (multi-line text)
2. Enable  Wiki Style Renderer.
3. Add some strikethrough text.

Expected Results

Strikethrough text should not be changed irrespective of expanding or compressing the custom field.

Actual Results

When the field is collapsed, the functionality is flawless, but when the field is compressed, strikethrough text turns into regular text.

Strikethrough text value is proper when the field is collapsed:

Strikethrough text gets converted into Normal text values after compressing the field.

Workaround

The functionality works fine when the field is collapsed 

Note: This issue can be seen for other formatting options as well :