Looks to me like you missed the part about using 90% of your max as a training max, or you have done enough cycles that the weight has caught up with you. Either way, you need to step back.
For instance, my DL 1RM estimate is 512. 90% of that is 460, which I use for my training max. On the 1+ set, I use 95% of 460, which is 440. Ends up really being about 86% of your max to start off. Also you might note, if you consistently miss 95% of your max, you probly overshot. And obviously if you change your stance, you are very likely changing your max.
Don't be afraid to start too light. You should be getting your 3+ sets for a good 5-8 or even more, and your 1+ sets for 3-5 or more, to start.