XProtect Corporate 2019 R2: Failing to recover frames using GOTO, NEXT, PREVIOUS commands. Live stream works...

Running XProtect Corporate 2019 R2. Authentication works, running and stopping live feeds works. GOTO, NEXT, PREVIOUS return empty ImageResponse messages, in response to a GOTO query given the current time in MS from epoche:

ImageResponse

RequestId: 9

Prev: 0

Current: 0

Next: 0

Content-length: 0

Content-type: application/x-genericbytedata-octet-stream

Hi.

Let me ask you a few questions.

Can you please tell me if the server is recording?

Is your Smart Client working and can do playback (when testing on the same PC with the same user and camera)?