All of us possess the ability to detect people's personality traits.
These stand out easily when we interact with another person.
Character, on the other hand, often takes conscious effort to notice because people don't necessarily reveal their characters all of the time.
The character of a person emerges under specific circumstances, whereas your personality comes through constantly in the form of your mental and behavioral patterns.
To be honest, it's normal to have difficulty judging character vs. personality.
We even have a tendency to attribute good character to pleasant personalities, but this is not a reliable way to judge this quality.