I made Properties panel part of my workspace. Saved the new updated workspace under same name (re-written).

Now when I start InDesign, last workspace gets automatically loaded but the Properties panel does not show up. Have to click in Reset workspace, only then it reappears.

Recently I added another panel to be part of my workspace (Bookmarks). This panel always shows up automatically upon launching InDesign, but the Properties panel is still missing along will other panels that are attached to it (layers, pdf comments).