Trouble accessing the Cursor to edit in Numbers on iPad

I'm using an A17 iPad Mini 7th gen, and working in a Numbers spreadsheet that contains information (and data). I want to edit the text in a cell, but struggle to get a cursor to appear. The instructions say to SINGLE tap on the cell to select it, pause, then DOUBLE tap on the cell to get the cursor to appear – except that's not what happens.

Sometimes, double tapping highlights a word in the text. If I get that, I need to single tap a 4th time to deselect that word, and get the cursor, then tap a 5th time to put the cursor where I need it. But that's rare.

More often, absolutely nothing happens when I double tap. The cell is still highlighted, but nothing is selected, and no cursor appears. I can double tap many times and achieve nothing. I can change how fast I double tap, yet still nothing happens. If I type something, I replace the entire contents, and I don't want to do that. Long pressing achieves nothing. When I get stuck like this, I often try tapping on a different cell, then I tap again on the cell I want to edit to re-start trying to edit, then try double tapping again. It can take dozens of attempts to get the cursor to show up, and when it does so, I have no idea what I have done differently. It seems random, and it's very frustrating to do this basic, essential task.

What am I doing wrong?