RTE plug-in strips off the data attributes(eg:data-link) when we save the RTE dialog. Any additional configuration available to avoid this?
You'll have to adjust the xss config to avoid the antisamy configuration to strip off these attributes.
Once you click save, Check the error.log that would provide the message that would give you an idea that antisamy is at play.
To fix this: You can follow (1) on similar lines.
(1) : XSS Filter issue with the target attribute of the a tag