Getting deserialize object error with 50 % pods having 7.8 version of Camunda and 50% pods having 7.12 version of Camunda

We are planning to migrate the Camunda version from 7.8 to 7.12 and planning to go in production with 50% traffic in 7.12 version and 50 % in the old 7.8 version. We are getting below error with 50 % pods having 7.8 version of Camunda and 50% pods having 7.12 version of Camunda and both versions of Camunda are connected to the same database. But I am not getting this error if there is 100% traffic of either 7.12 version or 7.8. It looks like there is an issue if serialization is happening in one version and deserialization is happening in different versions. Please help here.
ERROR Details:
Cannot deserialize object in variable ‘serviceAvailabilityResponse’: ENGINE-09017 Cannot load class ‘com.fasterxml.jackson.databind.node.NodeSerialization’: com.fasterxml.jackson.databind.node.NodeSerialization Status : 500

This is clearly the problem - the engine is not designed to work this way.

Thanks for your quick response.