1. `copy_cache` in `models.py` recursively copies the caches to environment, 
2. which in
```python
def _compute_related(self, records):
        """ Compute the related field ``self`` on ``records``. """
        others = records.sudo() if self.related_sudo else records
        if records.env != others.env:
            copy_cache(records - records.filtered('id'), others.env)
        values = list(others)
        for name in self.related[:-1]:
            values = [first(value[name]) for value in values]
        for record, value in zip(records, values):
            record[self.name] = value[self.related_field.name]
```
3. copies failing cache values that have been produce previously by this line:

`models.py : def _prefetch_field()`
```python

        try:
            # THIS ONE
            result = records.read([f.name for f in fs], load='_classic_write')
        except AccessError:
            # not all records may be accessible, try with only current record
            result = self.read([f.name for f in fs], load='_classic_write')
```
I checked it's exactly the same `FailedValue` object, which is later accessed without intent (not refreshed) by the fact that the buggy environment is copied to sudo (and not refreshed).


attrs['model_name'] = model._name
        attrs['name'] = name
        
        if attrs.get('compute'):
            
            attrs['store'] = attrs.get('store', False)
            attrs['copy'] = attrs.get('copy', False)
            attrs['readonly'] = attrs.get('readonly', not attrs.get('inverse'))
        if attrs.get('related'):
            
            attrs['store'] = attrs.get('store', False)
            attrs['copy'] = attrs.get('copy', False)
        if attrs.get('company_dependent'):
            
            attrs['store'] = False
            attrs['copy'] = attrs.get('copy', False)
            attrs['default'] = self._default_company_dependent
            attrs['compute'] = self._compute_company_dependent
            if not attrs.get('readonly'):
                attrs['inverse'] = self._inverse_company_dependent
            attrs['search'] = self._search_company_dependent
        if attrs.get('sparse'):
            
            attrs['store'] = False
            attrs['copy'] = attrs.get('copy', False)
            attrs['compute'] = self._compute_sparse
            if not attrs.get('readonly'):
                attrs['inverse'] = self._inverse_sparse
        self.set_all_attrs(attrs)