Query is slow for certain users
If the parameters are the same (I'm assuming that's what's meant by exact same query), it shouldn't be parameter sniffing (users get a bad plan for the wrong parameter(s)), but rather users are getting different plans for the same parameter(s). It could be because of settings like quoted_identifier and arithabort, which you can compare in sys.dm_exec_sessions for the fast user and the slow user, or it could be because they have different default schemas and objects are referenced without the schema prefix. Parameter sniffing may still be involved (hence why one of them has a bad plan).