The update to 2.2.7 seems to have broken the support of MockBean for interfaces it seems.
I tried mocking a Feign client with MockBean but the real Feign client is used instead of my mock, so the test fails.
I have create a sample project showcasing the issue with springmockk (which ported this change) and mockito: https://github.com/hikaru-shindo/springmokk-mockkbean-feign-error-example
Downgrading springmockk to 2.0.1 (not part of THIS report) and Spring Boot to 2.2.6 (for mockito test) will make the tests pass.
My bug report to springmockk suggests the problematic change is in https://github.com/spring-projects/spring-boot/commit/b9c2b7b257c0f36ee489fcc2cabda2c17cc19908.
Comment From: wilkinsona
Thanks for the report. This is a duplicate of https://github.com/spring-projects/spring-boot/issues/21379. It should have been fixed by https://github.com/spring-cloud/spring-cloud-openfeign/issues/337.