The new versions of CyberLink Director Suite programs, including PowerDirector 18, AudioDirector 10, and ColorDirector 8 or later versions uses OS technology to support Dolby audio.

The Dolby audio (decode/encode) feature is included in the Windows operating system (Windows 10 and Windows 11*). PowerDirector 18, AudioDirector 10,  and ColorDirector 8 or later versions use the operating system's technology to support the Dolby audio* feature (importing/exporting video files with Dolby audio). CyberLink does not provide the codec for Dolby Digital audio in the product.

For Windows 7: 

Windows 7 platforms do not support the Dolby audio feature. If you encounter the condition that Dolby files do not have sound after they are imported into the programs mentioned above on Windows 7, you are recommended to upgrade your operating system to the latest version of Windows 10 for the latest multimedia editing compatibility. 

* For Windows 11: 

According to Microsoft's official announcement, beginning with Windows 11, version 24H2, released in Oct 2024, the AC-3 (Dolby Digital) codec is no longer included in Windows. If your platform is a clean install of the latest Windows 11 version 24H2 or later, you may encounter issues such as being unable to import Dolby files or having no sound after importing them into the programs mentioned above. We recommend importing videos with a supported audio codec (e.g., AAC) or transcoding the video to a supported audio codec.

Or,  if Windows restoration is an option for you, you may restore your Windows OS to a previous version (e.g., Windows 11 version 23H2), which includes the AC-3 codec, to edit Dolby files further.

Here is the announcement from Microsoft for reference:
Codecs in Media Player

The Dolby audio export feature is no longer supported for AVCHD/Blu-ray/DVD video discs. You are advised to export the audio as LPCM format for video discs.

For more questions about the Dolby audio compatibility, please contact CyberLink customer service for further assistance:
https://www.cyberlink.com/support-center/contact-support