Userid and profiles merging

My issue:

User browses the site and has 80+ returning visits. They have a userid set, and I can see all of their histories with their userid

They open an incognito browser session, 2 returning visits.

Matomo shows this as two sessions.

The incognito browser logins and we can see their userid updated in Matomo.

Problem:
the non-incognito and incognito do not show up together when I browse the profile. In other words, they’re not actually linked.

Is this by design? I want to see all their sessions by userid…