Hello there,
I think there is a misconception. There are no free 25 that can expire. Its added to your uploaded amount automatically. And after that its counted as any uploaded amount. There is no free and there is no expiry. Only the reward.
If your ratio drops its because you are downloading. This is normal.
The wins you are talking about was last year, in 2022, so whatever your ratio is now, its rather you downloading.
In the end you won (25 x 2) 50 GB last year for winning two competitions and was rewarded them to your account. You also gained even more GB's for your correct picks in competitions in general.
In total during the year 2022 you won + 105.60 GB in the competitions. That's probably why you have a great ratio