Opera v. 68.0.3618.125
Windows 10 v. 1903

I've been away for a few months and kept using Opera on my laptop, all synced up to my account. Yesterday I came back home and on my main PC Opera won't sync to my account.
It says that I'm correctly logged in, but I have a yellow warning icon over the Sync icon (top right) and when I press it it keeps loading with no results.
I've tried to logout and back in but with no success.