How do I get the last rounding in the last corner?

Question

Everything is in the title

How to get the last rounding in the last corner in the code below?

\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}

\draw[fill,blue!50,rounded corners=0.5cm] (0:3) to[bend right=30]  (120:3) to[bend right=30] (240:3) to[bend right=30] (360:3);
\foreach \aa in {0,120,-120}{
\draw [fill, blue!50] (\aa:2.2) circle (0.6cm);
\draw [fill, white] (\aa:2.4) circle (0.3cm);
}
\draw[fill,white] (0,0) circle (2cm);
\end{tikzpicture}
\end{document}

Answer 1

rounded corners has "several pitfalls" - avoid it here.

\documentclass[tikz, border=1 cm]{standalone}
\begin{document}
\begin{tikzpicture}
\fill[blue!50, bend right=30] (10:2.8) to (110:2.8) to (130:2.8) to (230:2.8) to (250:2.8) to (350:2.8) to cycle;
\foreach \aa in {0,120, 240}
  \fill[white] (\aa:2.4) circle[radius=0.3];
\fill[white] (0,0) circle[radius=2];
\end{tikzpicture}
\end{document}