F2 (edit cell contents) also selects some or all of the text, but only in one file/workbook

Since this is only happening in a new sheet, I expect I fat-fingered some, unknown to me, setting toggle.
In all my other sheets, if I select a given cell and press F2, Calc switches to cell edit: can enter or edit cell contents, if there is pre-existing contents then cursor is placed at the end of current contents. In my problem sheet, pressing F2 switches to edit mode, but also selects all or most of the current text. Strange, I just checked every (all 6) populated cells in this new sheet. Except cell c2, all the others, pressing F2 selects all current contents. Cell C2 contains "FB, R.O. Rehabs’ and pressing F2 on it results in all but the first two characters being selected. Then after having repeatedly selected nearly every populated cell and pressing F2 to confirm what I’m reporting, the behavior suddenly stopped. It’s fixed, I guess. But I’m certain I didn’t fat-finger a fix. What happened?