Added and Removed tags are cleared in inherited gameplay tag containers. This came from the following UDN: https://udn.unrealengine.com/questions/587982/ue-master-tags-in-finheritedtagcontainer-do-not-sa.html
Create a new GE. Add a new tag to the Granted Tags. Compile the GE. The newly granted tag will be cleared instead of being used to rebuild the correct full list of granted tags.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-95207 in the post.