Using the WebSocket server, when the same client calls multiple time the subscribe method, only the last subscription receives all the events of the previous ones.
example:
subscription1 = tm.event = 'NewBlock'
subscription2 = tm.event = 'Tx'
In this case, subscription2 will receive the new blocks but subscription1 will not.
This came from the WebSocket handler that had the declaration of the rpcrequest moved and so overridden for every request and given in the JSONReq client context (so the id of the subscription was not the right one).
This fixes the issue by simply declaring the rpcrequest inside the loop so every request will create a new object without overwriting the previous one.