I've already mentioned that BNA was End-of-Life and will/is (be) replaced by SANNav.
As of the time of this writing any BNA version older than 14.4.1 is no longer supported. This basically means that your BNA (or any OEM version) older than that release is not being looked at when yo have a problem with it.
This also includes the embedded service interfaces like SMI-S agent and all REST interfaces. i.e. the SMI-S agent and REST API are no longer supported on ANY version.
BNA is currently in sustain engineering mode so only highly critical patches will be provided. New function and feature requests will be denied. The expected latest version will be 14.4.x and full End-of-Support will be August 2nd 2022. This should give you enough time for budgeting and planning the purchase and implementation.
Be aware that more stringent support restrictions are also being implemented on FOS so keep an eye out one that.