Couldn’t synchronize the staging environment to live website. What’s the issue?

I've created a staging website a few weeks ago to redesign my website from scratch.
I used to have flothemes, now created my new website using kadence. All new and pretty big I think.

I'm finally finished and ready to set the staging site live.
I went to "hosting-configuration" on my dashboard, then to "staging-site" and wanted to sync it with my live website.

It started, but then an error appeared saying "We couldn’t synchronize the staging environment." and the option to try it again has disappeared.

I cleared my browser cache and cookies and also tried with a different browser, but the option to try it again remains disappeared.

Maybe it' s some plugin that is the issue, so I wanted to disable some of them that might be the problem temporarely to try the sync again, but well, I can't anyway as long as the error message is still there.

Opened a ticket with WP support but the person in the chat told me that they have to investigate the issue further and will email me…so that will take a while.

Any idea how I can at least make the error message disappear, so I can try my luck again?

Thanks!