I just found that many tabs in my Safari Web Inspector are no longer there.
For example, previously, I have the following tabs in Web Inspector:
Inspector:
Elements;
Network;
Sources;
Timelines;
Storage;
Graphics;
Layers;
Audit;
Console;
Console;
Sources;
Audit;
My OS: macOS Catalina, 10.15.7
Xcode: 12.4
Safari: 14.1.1