When I just type "i", intellisense changes the character "i" to "await", and make that method async. It really bothers me when I code for statement.
It occurs when I program only in C#, not in other languages.
i had the same issue in VSCode and it disappeared when enabling the EXPERIMENTAL feature "Omnisharp: Enable Async Completion" in the settings of the "C# for Visual Studio Code"-extension. (That the feature also has "async" in its name is probably coincidential :). Seems strange to me, maybe a bug.)