[TYPO3-english] @validate ignored when model extends another model

[Jennifer Koenig]

I'm using TYPO3 7.4.

I have one abstract model (baseRequest) and two model that extend it (bookingRequest and availabilityRequest). 

For bookingRequest I have a Fluid form with the object "newbookingRequest". Its fields are properties from both baseRequest and properties specific to bookingRequest. On submission of this form, ONLY the @validation annotations of the abstract model (baseRequest) are validated, the @validate annotations of the bookingRequest model are ignored. If I cut a property and its getter and setter out of bookingRequest and paste it into baseRequest, this field is then validated on form submission.

I found something about this under this link and implemented the patch in my own code

https://forge.typo3.org/issues/70017

However, the behavior remains the same.   Is there something else I need to do (besides update to 7.5 right now)?