A person who is often late can be described as 'unpunctual', although this isn't a very common word in the negative form. Note that 'late' is an adjective, so you can't say 'a person who usually late'. You need to have a verb in this phrase - for example, ''a person is who usually late', 'a person who usually arrives late' or ''a person who usually comes late'.

They could be described as a tardy person. Bob

I guess maybe is latecomer?