Issue occurs for Acrolinx for Mac PowerPoint plug-in only. For Acrolinx for Mac Word plug-in, hyperlinks are preserved even after you insert Acrolinx suggestions from the sidebar.
If Acrolinx finds an issue on the display text of a hyperlink, and you insert a suggest from the sidebar to replace the text, then PowerPoint removes the hyperlink for that text.
This behavior is a limitation of PowerPoint. If the plug-in changes any part of the hyperlink text, PowerPoint removes the link.