I've been experiencing an issue lately and I am able to consistently reproduce it. I figured out what the issue is, and hoping it can be fixed soon.
Whenever I use autocomplete with tab to replace a statement, I am left with trailing characters which I then need to manually remove. More specifically, the number of trailing characters that remain are equal to the number of characters I typed.
In this example, I am trying to replace "RunningUser" with "CurrentUser". After typing "cu" I expect to press Tab and have Resharper correctly replace it. However, I am always left with trailing characters.
Notice the extra "er". It consistently keeps the number of characters I typed in. So, if I don't type anything and just press tab, it works fine. If I type "cu" it keeps "er", if I type "cur" it keeps "ser", etc.
I can provide more info if needed. Please let me know if this is an option I can toggle or when this can be fixed. I am using VS 15.3.2 and Resharper 2017.2.
I also reported this on YouTrack - https://youtrack.jetbrains.com/issue/RSRP-466251