Did you change some gear or a blessing or even just throw in some extra glyphs.  

Anything that can change the turn order could possibly mess you up.   

No, and dropping 4 stages is more than a new glyph

You just said "after some upgrades", which means you clearly made changes. Those changes could have altered the turn orders enough to cause your runs to fail.

Changing speed by even one point on a toon could be enough to throw off the turn order.  That is all it takes, just like in a speed-tuned Clan Boss team.

The stats on Sand Devil have not changed since the big nerf last year, so whatever changed is on your end.