I reached Tier 18 well before I reached the level requirement of 48 to receive the Smoldering Ashes. After reaching 48, I did not receive the Ashes, but they show as having been received.
Imgur links (add missing period) for Tier 8 (i.imgur com/VPmiAjb.jpeg) and Tier 18 (i.imgur com/V2SOK9j.jpeg) with only 1 having been used. (Why the bloody hell do you have the formatting option to add a hyperlink if you can’t include links?!)
Same for me with first ash, reach lvl 28, ash redeemed, not by me, where is it??
I had this happen on the lvl 44 ash. Logged out and back in and it showed up to use on the blessings
It takes a lot of time to give my ash back, but it came. Why was it redeemed by himself is the new question.
I have the same problem, it says I redeemed the Ashes on Tier 8, but I dont have any usable Ahses available for the Season Blessings. Where did it go?
Same here. I suppose to have 3 of them already but I only got 1.
Although I reset the allocated one and now I see all three there and can allocate them.
I am currently missing 3 ashes, I have 2 total at level 71, I just reset mine as StelarMonkey said and it worked… so thanks 
The also Happens in the Season 5, although I’m supposed to Get Smoldering Ashes at Tier 8 for A Level 45 Character, It says I got it , but there is no item. The next Ash Drop is at Level 55, I my need to wait to confirm. Only a Level 45 Barbarian currently.