Does any grammar (book or theory) classify 'where' and 'when' as pronouns?
Collins:
where
pronoun
14. the place or situation in, at, or to which
he lives two miles from where he works
15. what or which place
where do you come from?when
- pronoun You use when to introduce a clause which specifies or refers to the time at which something happens.
He could remember a time when he had worked like that himself.
She remembered clearly that day when she'd gone exploring the rockpools.
In 1973, when he lived in Rome, his sixteen-year-old son was kidnapped.