iLvl incorrect after gear change

https://www.warcraftlogs.com/reports/wA1pRfCFdLVTMJY4

Corv is correctly detected as iLvl 400 during the first kill. After that fight, and swapping from 2H to 1H+OH, the OH is not detected and Corv’s iLvl is incorrectly reported at 375 for each of the following kills.