Not all the berries are doing this. Pollination issue?
Heat stress can cause double fruits…
im not a plant pathologist just my observation. YMMV.
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I grew logans a few years and every year got a few double berries like that.
TNHunter
The original blossom caused that partially doubled berry.
How many doubled berries do you have compared to the whole crop?
Otherwise, your Logans look just like mine. If you let them get too dark red for too long they soften and are hard to pick intact, although the flavor remains.