🇺🇸United States @mallory99

I ran into this issue today, with taxonomy term migrations in a custom module. CSV term migrations (in the same module) worked normally for a different vocabulary. The migration ids were correct and cache rebuilding made no difference.

On a hunch, I ran drush migrate:upgrade --legacy-db-key=migrate --legacy-root=http://[installation] --configure-only. After doing this, suddenly the rejected migrations ran.