A macOS update can rebuild indexes, reset permissions, migrate login items, and create temporary background work.
Allow initial indexing and cloud synchronization to finish before judging performance.
Review Full Disk Access and Login Items for the active diCleaner copy. Check startup items for new or migrated entries, but do not disable an unfamiliar system component.
Confirm visual settings and any macOS permissions used by the features you rely on.
Use Activity Monitor and Overview to identify persistent issues after the system has settled. Avoid repeated memory or cache actions during normal post-update rebuilding.