QUESTION: User left the company, leaving some items encrypted. How to retrieve those items?

You can do this by directly doing some "cleanups" inside the database.

Get the ID number of this user, and clear the field "restricted_to" inside table "items" where this ID is set.

Thanks for the tip. I will follow the steps and will post the results.

Unfortunately, I found the "restricted_to" field empty for all items. Any other ideas? I would appreciate any guidelines ...

You might also have other type of restriction stored in table restriction_to_roles.

Check what roles ID this user was related to his account and compare with role_id present in this table

Following the suggestion, I checked the table restriction to roles, but it was empty.

Luckily, I retrieved the items in another way: I wondered what the table "cache" is, so I searched through it and found some historical data. Realizing it might contain what I do need, I ran a simple query

SELECT * FROM `teampass_cache` WHERE author LIKE '<user ID number>' and folder LIKE '<folder name>'

and was able to see the hidden details.

I hope this can help someone else.

Thank you for your time and efforts.