If you are on a single site page, the synchronize button is missing from the top right, there’s only a very small on very low on the page where the connection status is stated.
It seems like there a display none in the responsive layouts css
@media only screen and (min-width: 768px) and (max-width: 1449px)
- display: none !important;
PS: this small button on the status widge is really difficult to access while on a mobile device.