I have a long signal with some intervals with NaNs. When I using matlab function fillmissing with fill the NaNs, there are still NaNs left.

sum(isnan(signalInterpolate))

ans =

      281556

signalInterpolate = fillmissing(signalInterpolate, "movmean", 80);
sum(isnan(signalInterpolate))

ans =

        3796

Could anyone explain why this happens? Shall I change the window size to avoid NaNs after fillmissing?