When you rotate a think-cell label by 90 or 270 degrees, non-numeric characters rotate as expected, but digits are not rotated or rotated by 180 degrees respectively.
Delete affected labels and insert them anew.
In Microsoft Office, the setting kumimoji can be applied when, for example, an East Asian language is selected as the default editing language. When text carries this setting, digits and non-numeric characters rotate differently.
Kumimoji can be applied by selecting the Vertical option.
Unfortunately, PowerPoint's programming interface does not provide a way for add-ins, such as think-cell, to recognize text carrying the kumimoji property.
We have filed a case with Microsoft to request the inclusion of this facility. If your company has a Microsoft Office Support contract and you want to contact Microsoft to ask for a fix, you may refer to Microsoft case number 114073011661262.