Is the list_of_employee_ids​ a valid list? What does the print statement output? See, e.g., the example in the official documentation (https://www.odoo.com/documentation/16.0/developer/reference/external_api.html#read-records):

ids = models.execute_kw(db, uid, password, 'res.partner', 'search', [[['is_company', '=', True]]], {'limit': 1})
[record] = models.execute_kw(db, uid, password, 'res.partner', 'read', [ids])

The list of fields to fetch is optional for a read request, so you don't have to use that. Why don't you use the search_read​ method instead? Odoo provides a search_read() shortcut which is equivalent to a search() followed by a read(), but avoids having to perform two requests and keep ids around (see documentation link above). E.g.,

models.execute_kw(db, uid, password, 'res.partner', 'search_read', [[['is_company', '=', True]]], {'fields': ['name', 'country_id', 'comment'], 'limit': 5})

I hope this helps!

Thank you!

One question: In some cases it works without the "fields_to_read"..... 

To be consistent on my side.... Can I add the "fields_to_read" to all my xml/rpc reads?

Regardless:  You have been a great help for me!  

Thanks again!