After 5 passages, my Caco-2 cells are exhibiting unusual behavior or morphological changes when cultured in DMEM with high glucose and 10% FBS. What could be the possible reasons for this?

Cell type: Caco-2

Medium: DMEM high glucose, 10% FBS

Number of passages: 5

Observations: Unusual morphology or behavior (specify what changes you've noticed, e.g., cell shape, attachment issues, or growth abnormalities)

Has anyone encountered similar issues with Caco-2 cell lines after multiple passages, and what strategies can be employed to mitigate or correct these changes?