Helped a client recently with a TV issue.
The Sony Bravia was setup using WiFi, but the iPlayer was forever pausing and stuttering on playback. The router was close, just one wall away. First thing, we hard wired the TV with an Ethernet lead and reset the network wizard. Tested, got the same “infinity circle” between sporadic video playback.
Then we downloaded an uptodate firmware. The automatic download said it was “uptodate” but there was a newer version on the internet. We downloaded it and copied over to an USB stick.
Once we had upgraded it, and iPlayer still did exactly the same. Back to the shop for a replacement!!