Chinese Characters are Overlapping/Concatenating on PPT files

Problem

On the PPT preview, when using Chinese characters (in this case with font Arial Unicode) some of those characters are overlapping.

Environment

Confluence Version: 7.4.4

Java version: AdoptOpenJDK 1.8.0_252-b09

Steps to Reproduce

1. create a PPT file with Chinese characters using Arial
2. Upload to Confluence
3. Look at the preview

Expected Results

Preview shows the PPT file with all text readable.

Actual Results

Some characters are stacked on each other and can't be properly read.

Workaround

Upgrading to Confluence 7.8.0 or newer may fix this issue as the underlying library that renders Powerpoint files underwent a major upgrade in that version.

Alternatively upgrading to JDK 11.0.7+ may also resolve the issue