2 of my characters won't let me play on them now.

Hi,
for some reason my highest level character randomly wouldn't let me play on it and then I played my second highest level character to lvl up and play on it instead because someone in game told me to wait a few days.

Now, both of my highest level characters exit out of the game on the loading screen for both. Any idea why this is happening?

Also, I recently leveled to 73 on league and then right after beating the campaign it kicked me off and I couldn't get back on my character.