Memory Tear's missing?

I'm not sure what the cause of this is but my memory tear generation seems to be bugged.

I've ran several hundred (300+) maps without seeing a memory tear now after finishing my last sequence, full clearing each map.

I'm fairly confident I should have seen one by now based on my previous spawn rate before they stopped spawning.

I think i have the same problem , i have done hundreds of T16 and T16.5 and dozen of T17 and just haven't see anymore Memorys at all in any map. And i'm just missing 1 Memory Altar for the challenge.
It's not possible that after so many maps i wouldn't have seen at least 1 more time

Note that only maps on the atlas can generate tears. Shaper maps and T17's are not on your atlas, so tears can never generate.

I'm still theorizing that base map mobs is the best way to generate tears. I was getting quite a few doing shrines and pack size scarabs, with my best record being 3 in a set of 20. Doing strats without that atlas strat has netted far less tears.

Same for me