Wishing wells have been permamently replaced by Djinn from Spire (confirmed on Facebook live) to lower the ammount of diamonds players could get for free.
During Summer Sirens 2019 and Autumn Zodiac 2019 players farmed around 11-12 Sirens fully leveled and some reached 8 fully leveled sets of bears (24 buildings on lvl 10), by using 1st day's bug of 180 currency per quest (max on 2nd day was 80), permamently destroying game balance (they win every tournament in rankings now).
They farmed hundreds of wishing wells as daily rewards, so they have them stored for next years to come to have free diamonds.
Blame them for the changes. Now they have wishing wells for next years and all players can't get wishing wells anymore.