This issue has become worse and worse with the recent IDE releases. When I first open Arduino IDE and click on the Tools menu, it appears on the screen immediately. However, as soon as the message "Updates available for some of your boards and libraries" it becomes incredibly slow, and it can take up to 20 seconds from I click the Tools menu before it appears. While I'm waiting, the cursor is just a spinning ball.

Is this somehow caused by the boards manager? FYI I'm running Arduino 1.8.10 and MacOS 10.14.5