This is a known problem. I'm happy to provide you with a BLOG entry on this: https://www.spickipedia.com/index.php/samsung/samsung-das-angeschlossene-usb-geraet-wird-nicht-unterstuetzt.html, the adapter mentioned is this one: Samsung USB-C Audio Adapter (USB C, 3.5mm)
The audio cable with 3.5mm jack to USB type C only works with the Sonos Era 100 in combination with the Sonos input adapter, which is required separately. The Era 100 does not have a direct 3.5mm input, but a USB-C port into which the Sonos input adapter is plugged. The 3.5mm jack cable is then connected to this adapter.
This means that the cable can be used when connected to the Sonos input adapter to connect an external audio source to the Era 100. Without this adapter, the cable is not directly compatible.
According to the specifications, the cable is designed to connect a source (e.g. a mobile phone) with a Type-C output to a playback device with a 3.5 mm jack connection. What you want would be the opposite, so to speak, which is why I can't guarantee that this will work the way you want it to.
According to my research, the USB-C Port of the JBL Flip 5 is only for charging and is not able to carry an audio signal. If your Samsung TV supports Bluetooth, you can try to connect your Flip 5 wirelessly (This will introduce a slight delay with the picture though).