How to record a three and a half minute song

Every time I try to record something at least three and a half minutes long something goes wrong. The play back only plays about half of what I recorded and then starts from the beginning just repeating the first half. The other part does not play back.
Sometimes it stops recording at about the halfway point and stops.
Can anyone help solve this ?
Thank You.

Which version of Audacity?

How are you starting playback? Are you clicking on the “Play” button?
(Note that “Shift + Play button” will “loop play”)

I have 2.2.1 version of Audacity.
Yes, I just click Play .
I am trying to download and install version 2.3.3
It says on it Audacity 2.3.3 (Flathub))
What does Flathub mean?? Is this the one to install? I have Linux Mint 19.1
This is from the Official Site

I would recommend you stick with the 2.2.1 version.

“Flathub” provides “Flatpak” builds ( Because Flatpak apps run in a “sandbox” environment, this can cause problems if you try to access external resources. Such problems can be confusing.

Am I understanding this correctly: When you click the “Play” button once, Audacity will play the first half of the track repeatedly until you press the “Stop” button? (I’m hoping that I’m misunderstanding what you mean).

You understand Correctly. This is what has happened: I recorded something about three and a half minutes long.
When I try to play back, I press the PLAY button and either of two things will happen: It will play About half the recording and then go back to the beginning and start again OR it will play about half and then SHUT OFF.

It sound to me as though you have the first half selected.

a) with a selection present when you press Play Audacity plays only the selection and stops

b) with a selection present when you press Shift+Play Audacity plays only the selection and loops

Both are intended designed behaviors for Audacity.