I thought that Sync was broken this AM; looks like it's not, just seems very slow (even to fetch a single bookmark). I'm not seeing an obvious way to force a sync in Fenix (tried pull to refresh, etc), so it's possible that this is simply user error....but I wanted to file a bug anyways as it's something that I could see being easily mistaken for "sync is broken".
To repro:
I _think_ this is new. I have tested (while pointed to spanner) previously and did not see this happening. Bookmarks/etc appeared quickly.
I'm not seeing an obvious way to force a sync in Fenix (tried pull to refresh, etc)
If you go into settings and click on your account, it should show the sync options page with checkmarks for whether to sync bookmarks/history/whatever, and at the top of the page a "sync now" option.
Thanks, @rfk - manual sync appears to not be delayed either; my test with a bookmark appeared quickly. I'll close this one.