I just posted this in Github also but this worked for us.

"I know this post is old but I wasn't getting anywhere with the same symptoms for the past few weeks. We have local development VMs that were working fine with the homepage UI load but migrating to our more secure AWS solution is where we ran into issues. The setting that reaches out to airflow to pass data is what was causing the problem. Runs, Last Run, and Recent Tasks all spun for minutes before finally showing results. Specifically, I changed the variable AIRFLOW__USAGE_DATA_COLLECTION__ENABLED from enabled=True to enabled=False. Those fields populate almost instantly now."