For brand-heavy PowerPoint work, I use Plus AI. It maps directly to your master...

https://lima-wiki.win/index.php/Why_Are_My_Charts_Exporting_as_Images_from_Gamma%3F_A_Professional%E2%80%99s_Guide_to_the_PPTX_Friction

For brand-heavy PowerPoint work, I use Plus AI. It maps directly to your master slides, so you avoid those annoying font substitution errors after export