What's happening with Raspberries

  Morning all on yet another hot day.
 We bought 2 Raspberry canes from our local ASDA  in 2019, 1 is early summer fruiting & the other is late summer, last year we expectedly didn't get many fruits off either but this year we are getting loads off the early 1 & a few off the late 1 already  .  Down to the question :- Most of these fruits are lovely & big but in the last week some of them are ripening with like a crystalized appearance on 1 side of them    We have been feeding them once a week & in this weather watered every night from water butts .
Any ideas gratefully received, thanks in advance.
Keith/Sharon.