Kevin
Yes the league search feature is a bit of a waste of time at the moment.
A tip given to me by another very experienced manager. Click on the "Spectate" icon at the time you want to race and you will see all of the races that are currently running. This will also show you the average rep for the league, the number of laps (indicating race length) and how many cars are competing in the league/tier you're interested in. You can even filter by tier, getting rid of the tiers you are not interested in.
I hope this helps.
Thanks