When i try to create a dashboard like this:
model: Sale.order
operation: sum

measured field: total
group by: seller (user_id)

I get this error:

Traceback (most recent call last):
  File "/opt/odoo18/odoo/http.py", line 1957, in _transactioning
    return service_model.retrying(func, env=self.env)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/odoo18/odoo/service/model.py", line 137, in retrying
    result = func()
             ^^^^^^
  File "/opt/odoo18/odoo/http.py", line 1924, in _serve_ir_http
    response = self.dispatcher.dispatch(rule.endpoint, args)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/odoo18/odoo/http.py", line 2171, in dispatch
    result = self.request.registry['ir.http']._dispatch(endpoint)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^
  File "/opt/odoo18/odoo/addons/base/models/ir_http.py", line 329, in _dispatch
    result = endpoint(**request.params)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/odoo18/odoo/http.py", line 727, in route_wrapper
    result = endpoint(self, *args, **params_ok)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/odoo18/addons/web/controllers/dataset.py", line 35, in call_kw
    return call_kw(request.env[model], method, args, kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/odoo18/odoo/api.py", line 517, in call_kw
    result = getattr(recs, name)(*args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/odoo18/custom/addons/odoo_dynamic_dashboard/models/dashboard_block.py", line 126, in get_dashboard_vals
    self._cr.execute(self.env[rec.model_name].get_query(domain,
  File "/opt/odoo18/odoo/sql_db.py", line 354, in execute
    res = self._obj.execute(query, params)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
psycopg2.errors.UndefinedColumn: column res_users.name does not exist
LINE 1: ...ALESCE(SUM("sale_order".amount_total),0) AS value,"res_users...

Seems like the error comes from a query on the database, this doesn't happen for every selectable field on 'group by', just by some like the seller field.