Will Wearing Old Aligners Work? (photo)

I did not wear a retainer for a few yrs. I have noticed the spacing in my teeth are starting to show. I went to my dentist and got the buttons back on.However, the aligner she said for me to wear, I could pop it out with my tongue. As I remember, the aligners should be tight for the first few days. So I felt it was not working. So last week I started wearing aligner 5 and felt the tension. Was I wrong with wearing an old aligner and the spacing between my teeth and the aligners, is that ok?