I don't know why, but in the past few days all of a sudden Resharper's intellisense stops working. All. The. Time. Constantly. When this happens, if I switch the resharper setting to use Visual Studio's intellisense instead of Resharper's own version, then intellisense starts working again. Switch it back to resharper: stops working. The only fix is to close and reopen my solution and then Resharper's intellisense starts working again. This is happening all the time throughout the day. I'd say easily a dozen times. I haven't changed any settings in VS or Resharper and I'm just working in the same project. To be more specific, what fails is after you type a . character you no longer see anything appear in the suggestion box. Nor do you see anything when you just start typing. I wish I could give a repro case but I can't. I sort of think it happens if I alt-tab after typing a . character on a variable to look at something and then come back but that could just be coincidence.
Edit: I'm using version 2017.3.3 built on 2018-03-02. Also I've tried clearing my cache a bunch of times.