Sorry that Layers panel in Photoshop is collapsed after the recent app update.
Which version of Photoshop are you using and what is your computer's operating system?
The Layers panel in Photoshop can be customized and set to unhide from the Photoshop's Window> Layers menu.
If that still does not keep it in place, would you mind restoring the preferences for Photoshop & see if it helps? See this article for reference: https://t.co/ulJI7cGn1G You may want to backup your settings beforehand: https://t.co/4dX7gkr36D
Since one of the latest updates, the Layers Panel is closed every time I open a document. Before that, the panel was always opened.
Technically, your Layers panel is open, not closed. Instead it is collapsed. Double-clicking the title bar "Layers" will expand it.
The panel dock cannot be larger than your screen, so the panels inside the dock will automatically collapse to their titles when they do not fit. You are not using the default Essentials workspace. When you go to Window > Workspace, you can select another workspace, reset the predefined workspaces, or create new workspaces with a new arrangement of panels.
The stumbling block in your setup is that your middle group with Adjustments, History, and Properties will resize to take up the largest size needed for any one of the three and will squish the lowest group to icons. You need to fix that.
If PS is not running full size in your screen, then Maximize it or at least resize the height. If it already is, then go on to the next step:
Start by choosing Window > Workspace > Esssentials, followed by Window > Workspace > Reset [Current] Workspace. Then add, remove, and rearrange panels as you desire. You might what to create a second dock next to the first for the panels that are tall. Then save your workspace.