Which text box in which tool is affected by this? Can you give an example?
What operating system are you on?
Thanks.

I am only aware of one Text tool In QCAD - the one in the LH toolbar. It affects both Windows and Linux versions and I found it from Beta to Final.

I tried changing fonts, but it has no effect.

Yes, there is only one text tool. There are various text boxes though, everywhere where you can input texts, numbers, etc.
Pressing the enter key has a different meaning in some of those text input boxes.

I'm not sure if I understand your report correctly:

Possibility A:

1. You start the text tool.
2. The text dialog is displayed.
3. You enter a text, for example "ABC".
4. You press the enter key to create a new line.
5. A special character is now displayed in the text editor instead of creating a new line.

This would likely be a Qt bug in combination with your keyboard configuration or layout.

Possibility B:

1. You start the text tool.
2. The text dialog is displayed.
3. You enter a text, for example "ABC".
4. You press the enter key to create a new line.
5. The text editor creates a new line as expected.
6. On the second line, you enter more text, e.g. "123".
7. You click "OK"
8. You place the text with the mouse in your drawing.
9. The text in the drawing is displayed without line breaks.

If this is the case, please make sure that you have NOT checked the option [ ] Simple text in the text dialog which is for simple, one line texts without formatting only.

Aha!

It was that simple text option! On the Beta it was switched off by default, but did not work in either mode.

On Final, it now makes a difference, but I missed clicking it.

Thanks a million.