UniFi Viewport suddenly VERY laggy

In our office we have a UniFi UNVR and to view the cameras live, we use a UniFi Viewport connected to a TV. This has worked flawlessly for about a year. All of a sudden, the live view is extremely laggy - like 20 seconds of lag time. We don’t see any lag when viewing live via a web browser via the NVR’s IP address. I’ve rebooted the Viewport, and it is already up to date on firmware. Has anyone else here seen this issue? Maybe a bad firmware update or something?