Thank you for reporting the issue.
We are currently investigating the problem.
InDesign TeamChris commented
I have the same problem. importing any transparent PNG shows black at the transparent part!!! Please fix it adobe!
indesign 2018 13.0.1Chris supported this idea ·
The issue has been fixed in InDesign 14.0.1Chris commented
jus post the issue then I found this. please fix it asap adobe. it's an important function that I almost use at every page for couple times. Indesign CC 2018 13.0.1 still having the same issue!!!!