Symfony version(s) affected: 3.4.41

Description
After merging symfony/validator@b50cd17 there is a possibility to have an exception (here https://github.com/symfony/validator/blob/b50cd17d3a154d096344ef22f54b8e3655cdf913/Validator/RecursiveContextualValidator.php#L317) when running down the code with null value as a result of $value->getPropertyValue().
For me that caused that the form errors were not mapped back to form children fields.

How to reproduce
Create a validator with getter validation, pass an object with such a validation to the form.