Unfortunately I went through the same glitch.. as it is a frustrating bug!
A random group of players have to face this each time we have responses as goals in our events. Sometimes everything flows smoothly.. then some time or the other the last response is not delivered to some players. After waiting patiently 9! hours.. yes I said NINE hours of trying ALL tricks & tips yesterday to reactive the deliveries.. I gemmed the last response to move ahead as to start crafting the other goals in step 9, cause I'm interested in finishing the event I started. This however should not be so and 8gems to remove my bug is alot I consider.. I would rather spend elsewhere in the game.
It's years we have this same problem and after many uses/tries/exercising the response system with use of gifts.. nothing changes.. it always returns to frustrate.. and ONLY with use of gems.. can be resolved if the players has interest in receiving the response that same day, otherwise it's delivered the day after. It has nothing to do with inactive nbrlists as developers may claim.. as the same all-active nbrlist is able to deliver within an hour if everything flows smoothly. It's a bug in the system, that no one is able to find nor correct.
We should receive 8gems free of use when we have the asking/response system.. for use on this bug.. cause it's going to happen each time. It's years it's there.. and besides frustrating it's aggravating and the victims just can't resolve and save their work due to time-out without paying.
Sorry about my rant.. I've been silently reading until now and as a faithful player, I'm stepping up and posting this annoying situation as it'll be passed over at the end of the event.. as usual, but it still exists!