RWS Subscription Regression: Payload size limit seems to have decreased in RobotWare 7.19 and 7.20

Robot Details:

• Controller: OmniCore

• RobotWare Versions Tested: 7.18.2 (Working), 7.19 (Failing), 7.20 (Failing)

• Interface: RWS via Python httpx client

We are experiencing a breaking change or regression regarding the maximum allowed payload size for RWS subscription requests. Our application subscribes to around 50 signals/variables, 20 of them being priority 2 (well below the limits).

We are using a single POST request to the /subscription resource. This configuration is working on RobotWare 7.18.2. However, upon updating to RW 7.19 and 7.20, this request consistently fails.

Observed Behavior:

• RW 7.18.2: Single POST request with 49 resources succeeds.

• RW 7.19 / 7.20: The same POST request fails. We discovered that we must reduce the request to approximately 12 signals (approx. 1400 bytes) for the request to be accepted.

• Workaround: If we split the 50 signals into multiple groups using smaller POST requests, the subscriptions go through, but the original single request method is no longer viable.

From this we have concluded that the failure appears to be related to the size of the HTTP POST body or the number of resources defined in a single request, rather than an exhaustion of controller resources.

Has there been an intentional change to the RWS server configuration in RW 7.19+ that limits the maximum size of a single POST request to the subscription resource? If this is a bug, are there plans to restore the previous payload capacity to remain consistent with 7.18?