Amazon as a source stock tracking issues
Incident Report for DSM Solutions
In the past days the outbreak of the Coronavirus caused issues with stock levels sync. The issues are on Amazon's website and isn't related to the DSM Tool price monitor feature:

Items seem to appear as Prime eligible where effectively when try to process the order the only shipping option is 1 month.

You can see a screenshot with example in this Facebook post:
Posted Mar 24, 2020 - 17:25 UTC
This incident affects: Price Monitor.