Is this happening when trying to correct some word? Is it like wrong word goes off while correcting the one?
If so, reach-out to support for the fix. This got fixed with AEM 6.4
The wrong word not going off while correcting the one inside component and also it's not highlighting in red color and not given any suggestion when we try to do Spell check how ever the same working for inline editing
Please find the screen shots Inside component RTE vs in line component editing component RTE
I am getting a spell check from the RTE in a component dialog.
I am not able to reproduce your results by using this package in this article -- Scott's Digital Community: Configuring Experience Manager Rich Text Editor Plugins in a Touch UI Component Dialog
I have installed the above package on new instance and it's working fine applied same to our component and it's working.
I am happy to hear it working. That is exactly why we attach packages to the community articles.