Possibly the worst listed bike I've ever seen which also means that you could be getting a CAAD 12 which looks in good nick and with a wheel upgrade for cheap:
Pretty sure that's an optimo. Lesser quality aluminium frame (apparently) fork is different and also no internal cable routing. They generally sell for £150-£250 on eBay stock.
Still thinking about it. A straight top tube, short drop brakes and no mounts don't strike me as being a Synapse despite the sticker. I think you're right and someone has bizarrely added the Synapse sticker.
Possibly the worst listed bike I've ever seen which also means that you could be getting a CAAD 12 which looks in good nick and with a wheel upgrade for cheap:
https://www.ebay.co.uk/itm/126470712582?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=GSzGKyGjR_W&sssrc=4429486&ssuid=WBZsvPhLTW6&var=&widget_ver=artemis&media=COPY