If you ship ahead of 1 day shipping, the AHT is learning that that ASIN can be shipped as 0 day handle time. We are seeing the same thing with going on and did a post here.
This AHT thing seem to start about 4-5 weeks ago. That is we when we spotted our first ASIN as 1 day handle time (we are 2 day handle time). We did a post on NSFE about it and the mod did a run around until finally understanding the issue but had no solution.
We continue to ship on the 2 day handle time schedule in hopes that the AHT program will straighten itself out (recalculate correctly). So far we have not had an OTDR issue even though we have shipped one day late with the “Late Delivery Risk” badge. We have only had one late delivery (one day late). We had emailed the customer prior to shipping that the expected shipping had been mis-calculated and gave the actual expected delivery by date. So far, we haven’t had a related customer issue.
If this continues, we will turn off AHT and go with our manual at item level 2 day handle time. There isn’t anything else that can be done.