Something related to a person not people in general

What is the word or phrase for something related to one person not people in general. For example:

This issue is very ???, it doesn't apply to other customers/people/users, so we skip it.

Solution 1:

There are simply way too many options, here are a few based on your context:

Specific

connected with one particular thing only

Personal

not belonging to or connected with anyone else

Individual

connected with one person; designed for one person

Peculiar

strange or unusual, especially in a way that is unpleasant or makes you worried

Eccentric

considered by other people to be strange or unusual

Rare

not done, seen, happening, etc. very often

Singular

connected with or having the singular form

Uncommon

​not existing in large numbers or in many places

Or, if you want to be more precise, you can use compound words to describe exactly what's causing the problem for this one person:

This issue is very device-specific, so let's skip it.

This issue is very location-specific, so let's skip it.

(Oxford)