Cassette player to Audacity

Yesterday I recorded several cassettes to Audacity on my laptop with no problems. I then exported them to MP3 and saved them on Google Drive.
Today I am trying to do the same thing but it is a conversation of my children when they were young. I cannot hear the adults asking the questions and can just barley hear the child speaking. I remember we had used a microphone for recording onto the cassette.
Why won’t it record like it did yesterday?
I am using Windows 10, Audacity 2.3.1, a cassette player, a new 3.5mm male to male stereo audio Aux cable which worked perfectly yesterday afternoon. I am going from the headphone jack to the microphone jack on my laptop. I am doing everything the same as I did yesterday. I posted this question over 2 hours ago and it was never posted.
Thank you for your help.

The microphone input of your computer is probably mono.
If the microphone input is mono, and your cassette tape is stereo, then the microphone input will only hear the right channel.

Ideally you should use a cassette player that has “line level” stereo outputs, and an audio device / sound card that has “line level” stereo inputs.
At a push, you could use stereo headphone out from the cassette player into “line level” stereo inputs.

If your computer sound card does not have “line level” stereo inputs, then you could get a USB sound card with line level stereo inputs (such as a Behringer UCA 202, for around $30).