There's a problem with term reference field's integration with views. When use term reference field as views filter, it will report a bug about 'core/modules/views/lib/Drupal/views/ManyToOneHelper.php '
Citing from #2012130: Regression: Views integration for "list" field types is broken
it will say 'query' is not a defined property for this object, and 'add_where_expression' is trying to work on non-object. Of course, the views is broken too. I tried taxonomy field's filter to test this code, because its field filter also extends "ManyToOne". It reports the same error.
Take a whole picture of this class, ' $this->query->add_where_expression' looks more like a typo, because '$this->handler->query->add_where_expression' has been used everywhere:)
This bug also shows for list fields, see #2012130: Regression: Views integration for "list" field types is broken