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4 of 4 Corrected wording a little. Sugar being hydrophillic isn't really the point but nothing in this answer is wrong anymore.

Sugar is hydrophilic, meaning it's attracted to water. Your water soaked/softened apples likely had a higher moisture content compared to your syrup. The water migrated out of the apples and equalized the sugar concentration. This process is referred to as osmosis.

Next time, try boiling the apples in that sugar syrup instead of just water.