This question (previously discussed on the IPUMS user forum here) is referenced in this Census Bureau note. Relating specifically to the 2018 5-year file, take note of the following from the CensusBureau note: " Revised data for 2017 will be used to create the 2018 and later 5-year ACS data." So, it sounds like this issue only persists for the 2017 1-year estimates for selected geographies.