Any idea about this UI error? APNX-1-4198-019

Hi everyone, we are seeing the above UI error. It's not reproducible in lower environments but in a test interface in production we are able to replicate this. But that too is an intermittent thing which is not happening always in test interface too.

Also, we have noticed that this is happening when we are saving list of variants(it is a list of record but the type is list of variants due to a for each loop) to a rule input which of the same record type(array) in a!save(). We could have added a!flatten() to fix this if this was reproducible in lower environments.

One more thing to add here is we have three servers in prod and this is happening only for server 3. 

Should we raise an Appian ticket as it seems to be more on Appian internal processing which is getting errored out. Please share your thoughts, would be really very helpful.

Error details - Expression evaluation error [evaluation ID = c84d8:58ae3] in rule 'XYZ' at function a!buttonWidget_23r3 [line 711]: An error occurred while executing a save: java.lang.ClassCastException: class [Lcom.appiancorp.core.data.RecordMap; cannot be cast to class com.appiancorp.core.data.FieldAddressable ([Lcom.appiancorp.core.data.RecordMap; and com.appiancorp.core.data.FieldAddressable are in unnamed module of loader com.appiancorp.tomcat.loader.AppianWebappClassLoader @5ec77191)