How to use the filter flag in drush config:status
If you look at the Consolidation\Filter\OperatorFactory class mentioned with the error, you'll see documentation at the top of the Class that outlines the acceptable syntax.
**
 * Convert a simple operator expression into an Operator.
 *
 * The supported operators include:
 *
 *      key=value           Equals
 *      key*=value          Contains value
 *      key~=#regex#        Regular expression match
 *
 * It is also possible to negate the result of an operator by
 * adding a logical-not operator either before the entire expression,
 * e.g. !key=value, or before the operator, e.g. key!=value.
 *
 */

Using the above documentation as a guide, the following all work for me - examples two and three should work for your example case.
// 1. Use the *Equals* option to show only the config entity with name &quot;webform.webform.contact&quot;
drush --filter=&quot;name=webform.webform.contact&quot; config:status

// 2. Use the *Contains value* option to show any config entity with name containing &quot;webform.webform&quot;
drush --filter=&quot;name*=webform.webform&quot; config:status

// 3. Use the *Regular expression match* option to show any config entity with name starting with &quot;webform.webform.&quot;
drush --filter=&quot;name~=#^webform\.webform\.*#&quot; config:status