Re: Enterprise Gateway won't update changed SSAS tabular schema information

 Is this issue on the original dataset that was published, or is it a copy of the dataset in a Content Pack that is not updating?

If it is the original, have you tried to publish a new PBIX file with the connection to the model?

Couple other troubleshooting questions:

Have you confirmed that the changes are showing in the Desktop file? Is it possible that you made the changes to the model in a local instance and did not deploy those changes to the "main" model that you are connected too?

Also check the actual model in SQL Management Studio to confirm that nothing got messed up in the deployment.