I wish I had checked this forum sooner. I had this same problem. I thought it was just my bad internet connection.

I eventually tried clearing all my cookies and cache but that didn't help.

​​​​​​It finally started working Monday evening (about 12 hours ago) so they must have fixed something.

If it ever happens again, you can use the app to search for fliggts. I discovered that workaround Monday morning.