Text selection in Phped doesn't work as in ordinary text boxes.

There are two unusual behavior about this matter:

1) In an ordinary text box, you select a piece of text, then left-click any point inside the text area, and text selection disappears. In Phped, text selection remains after you click a point in text area.

2) In an ordinary text box, you select a piece of text, then you type some other text by keyboard, and the selected text is replace by your new keyboard entry. In Phped, selected text remains selected, and your new keyboard entry is inserted at the cursor position.

I want the text selection feature of Phped to work as it does in ordinary text boxes.
What setting should I alter for this?

I just tested your observations in both PhpED 5.9 and 6:

1) Both versions of PhpED deselect the text if you quickly single left-click inside a text selection. If you left-click and hold, the text remains selected and then you can drag & drop it to a new position. You can disable that by ticking Disable code drag & drop in the IDE settings (not sure if that should really be an Editor setting?)

2) I couldn't reproduce this issue. If I select some text then type something, the selected text is always replaced with what I typed. I also could not find a setting to change that behaviour.

For me it behaves exactly as I would expect in any text editor.

I suggest going into the Editor settings and clicking the Reset button, then seeing if the behaviour changes.

It looks like you turned Persistent Blocks on.
So they are persistent.