I am aware of someone else who didn't get the achievement that was expected so I am wondering if any of all of the achievments requirements, especially the secrets ones,  were affected  or even changed,at the same time as the recent big update.

I did another 10 on top of the 350 and still got nothing. I do the player pic change so that way i dont loose count, so yes it was exactly 360 changes on something thats supposed to be 350. and got nothing. 

Hi Jarls! We would like to note that the mechanics of achievements in the game involves the players' independent search for solutions. After all, the path to the goal is no less interesting than the awards for achieving it.

The work of the Secret achievements has been tested many times, and we assure you that they work correctly. Please note that game mechanics involve an independent search for solutions by players. We cannot disclose the conditions for obtaining these achievements or the results of verification of their work.

We also inform you that any information about the Secret achievements, wherever it is posted, has no relation to Plarium and we do not guarantee its accuracy.
There are a number of conditions for getting the Secret achievements. The player must fulfill all these conditions, and only in this case, the achievement will be awarded.

If this does not happen, then this means that some conditions have not been met.

so then you did change the amount, funny people in my kingdom have it and they have done the exact same thing as i have done. Anyway im not wasting anymore gold on this one,  like pouring money down a bottomless pit lol. And thank you for responding 

And for people reading this i have a palace lv26 and did  410 pic changes and nothing. so either their palace lv has changed or the amount has, or both. either way it has changed. (and im not wasting anymore of my time and gold on it)

When you get one of these secret achievements, it does not tell you how to get the next level, but it does indicate the palace level needed, this part ought not to be open to question.

The  expected achievement mentioned in my earlier post has now been awarded, the reasons surrounding this  event remain unclear.