Seems that the new release by default starts the Embedded Mongo when it's found on the classpath instead of using the mongo template defined in the application.properties. The workaround is to temporary remove flapdoodle.embed from the dependency list even if it's in test scope
2020-06-24 09:22:53.048 INFO 51028 --- [ Thread-305] o.s.b.a.mongo.embedded.EmbeddedMongo : 2020-06-24T09:22:53.047+0200 I CONTROL [initandlisten] MongoDB starting : pid=51029 port=63665 dbpath=/var/folders/7x/ss8w17pd4bsfrg1x1t56sl00zq753h/T/embedmongo-db-20d4fbe0-abac-4715-8ae0-b863f7bc9627 64-bit host=M84452