`WrongMethodTypeException` with blackbird

After upgrading to Java 16 and Jackson 2.12 with Blackbird replacing Afterburner, we are seeing WrongMethodTypeException occur frequently. The strange thing is that this affects only 25-40% of requests. An identical request made repeatedly will fail at that rate.

Example stack trace:

```
java.lang.invoke.WrongMethodTypeException: expected ()ToIntFunction but found ()ToIntFunction
at java.base/java.lang.invoke.Invokers.newWrongMethodTypeException(Invokers.java:506)
at java.base/java.lang.invoke.Invokers.checkExactType(Invokers.java:515)
at com.fasterxml.jackson.module.blackbird.ser.BBSerializerModifier.createProperty(BBSerializerModifier.java:116)
at com.fasterxml.jackson.module.blackbird.ser.BBSerializerModifier.lambda$findProperties$0(BBSerializerModifier.java:64)
at com.fasterxml.jackson.module.blackbird.util.Unchecked.lambda$runnable$0(Unchecked.java:31)
at com.fasterxml.jackson.module.blackbird.ser.BBSerializerModifier.findProperties(BBSerializerModifier.java:65)
at com.fasterxml.jackson.module.blackbird.ser.BBSerializerModifier.changeProperties(BBSerializerModifier.java:49)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.constructBeanOrAddOnSerializer(BeanSerializerFactory.java:407)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.findBeanOrAddOnSerializer(BeanSerializerFactory.java:290)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory._createSerializer2(BeanSerializerFactory.java:235)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.createSerializer(BeanSerializerFactory.java:169)
at com.fasterxml.jackson.databind.SerializerProvider._createUntypedSerializer(SerializerProvider.java:1473)
at com.fasterxml.jackson.databind.SerializerProvider._createAndCacheUntypedSerializer(SerializerProvider.java:1421)
at com.fasterxml.jackson.databind.SerializerProvider.findContentValueSerializer(SerializerProvider.java:753)
at com.fasterxml.jackson.databind.ser.impl.PropertySerializerMap.findAndAddSecondarySerializer(PropertySerializerMap.java:90)
at com.fasterxml.jackson.databind.ser.std.AsArraySerializerBase._findAndAddDynamic(AsArraySerializerBase.java:311)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:115)
... 74 common frames omitted
```

This is occuring in a Dropwizard application.

Happy to provide more information as needed, and will continue to dig and update this issue with what I find.