I just changed my 5 star rating to 1 because of this
Talking to support doesn't work
If we all do the same ????
It's not that you havent got any opportunity to make these buildings.
The come by quite often, maybe not as much as you like but anyone claiming they havent seen or only 1 in 7 weeks like the TS hasn't checked all the recipe pools.
There is one pool of recipes every 6 hours.
New recipes are not the reason as those are added to the non building slots (and those that are added to the building slot are once only so if you make them and keep them in your inventory/city they never appear again)
The most important part is that you reset the timer at least once. you want those 4 opportunities per day you need them to reset at times you are able to see them.
For example if you sleep from 10 pm to 8 am you do not want a recipe pool to be not seen between those times
If I reset the recipes at 9PM I can see the last pool 1 hour before I go to bed. this pool lasts from 9 PM to 3 AM, the next one lasts from 3AM to 9 AM, this means that after waking up at 8am you have one hour to see the next recipe pool.
So you have to set your timers in a way that fits your RL habits. once you do it should not be that hard to see all 4 recipe pools per day.
On average you get about 3-4 combat buildings a week, sometimes less sometimes more.
But 1 in 7 weeks, thats a bit of a stretch, you can bet those recipes have been seen during the night in the pool he missed.
1 in 7 weeks is a 0.5% odd while in reality the odds are between ~10-15% since the slotted item change I lean more towards the 15% where pre slotted items it was more like 10%.
At least thats what years of tracking these buildings show. and I rarily miss a recipe pool.