nested enumerate behave strangely in beamer

Question

I'm working on a nested enumerate list where I'm trying to have \items to appear sequentially with the \setbeamercovered{dynamic}; however, for the last item of my list there appears to be a problem in that is not showing.

Maybe I'm doing something wrong without realizing it. Below a MWE, thanks in advance!

\documentclass{beamer}
\usetheme{Boadilla}
\useoutertheme[width=0pt,height=.5in]{sidebar}

\definecolor{bground}{HTML}{005EB8}
\definecolor{anti-flashwhite}{rgb}{0.95, 0.95, 0.96}

\makeatletter
\addtobeamertemplate{headline}{}{%
\ifnum\c@framenumber>1%
    \begin{tikzpicture}[overlay,remember picture,inner sep=3pt,outer sep=-2pt]
        \node[anchor=north east] at (current page.north east) {\includegraphics[height=\beamerheadheight,keepaspectratio]{example-image}};
  \end{tikzpicture}
\fi%
}
\makeatother

\setbeamercolor{frametitle}{fg=anti-flashwhite,bg=bground}

\begin{document}

\begin{frame}[t]
\setbeamercovered{dynamic}

\centering Some text:\pause
\vskip .25in
\begin{enumerate}[i]
    \item<2> first point
    \item<3> second point:
    \begin{enumerate}[a]
        \item<3-> additional info 1
        \item<4> additional info 2
    \end{enumerate}
\end{enumerate}
\end{frame}

\end{document}

Answer 1

With \item<3> second point: you forcefully remove the item and its children from the 4th slide. If you want to see the child item on the 4th slide, don't remove its parent.

\documentclass{beamer}
\usetheme{Boadilla}

\begin{document}

\begin{frame}[t]
\setbeamercovered{dynamic}

\centering Some text:\pause
\vskip .25in
\begin{enumerate}[i]
    \item<2> first point
    \item<3-> second point:
    \begin{enumerate}[a]
        \item<3-> additional info 1
        \item<4> additional info 2
    \end{enumerate}
\end{enumerate}
\end{frame}

\end{document}