Can teeth separate even if I wear my orthodontic retainer properly?

Even though it has been quite a while since my correction was finished, I am still wearing my retainer consistently.

However, recently I feel like the gap between my front teeth has widened just a little, so I'm worried.

I am wondering if it is possible for teeth to separate even if I think I am wearing my retainer properly.

I’ve heard that in cases like this, the teeth might shift slightly if the retainer is deformed or doesn't fit well, and I’ve also seen posts suggesting it could be due to insufficient wearing time, so I would like to know which cause is more significant.

Has anyone ever experienced their teeth becoming spaced apart even though they wore their retainer properly?

Did the dentist say that your retainer has loosened? Or were you told that your teeth have naturally shifted little by little?

I am also curious whether the issue was resolved by simply having a new retainer made, or if you underwent partial orthodontics or additional treatment.

Also, I would appreciate reviews and advice from those who have had similar experiences regarding whether there is a time when the retainer needs to be replaced after prolonged use.