PDF / Word export with lettered nested list is converted to numbered nested list

Steps to Reproduce

1. Create a page on Confluence
2. Add a numbered list, like this:

1. title test
2. title text
3. title text
4. title text

3 Select several lines and Indent them to the right by one level, so they look like this

1. title test
   a. title text
   b. title text
2. title text

4. Publish/Save page and export to PDF or Word

Expected Results

PDF / Word document with exact same nested numbered list as in step 4

Actual Results

A PDF / Word document with all nested lists converted to numbered format

1. title test
   1. title text
   2. title text
2. title text

Workaround

• Rename nested lists manually
• Issue was observed in 6.1.3 then fixed in 6.2.1 and then re-introduced in 6.6.1