It takes time for the humidity to be removed out of the air: a 'particular' cubic foot (metre) of air that passes over the coils can be cooled quite quickly, but won't be dehumidified as quickly.
So when the unit runs it can drop the temperature by the necessary (e.g.) 5F (2C), but it may only drop the humidity by 5%, when it needs to drop by (say) 10%. So a 'too-short' run-time can adequately cool the air, but not necessarily remove moisture.
It's also easier to generate 'excess' humidity by bathing/shower than it is to generate excess heat (cooking could generate both). So the humidity can creep up in value while the temperature stays more steady.
So when the unit runs it can drop the temperature by the necessary (e.g.) 5F (2C), but it may only drop the humidity by 5%, when it needs to drop by (say) 10%. So a 'too-short' run-time can adequately cool the air, but not necessarily remove moisture.
It's also easier to generate 'excess' humidity by bathing/shower than it is to generate excess heat (cooking could generate both). So the humidity can creep up in value while the temperature stays more steady.