Command block output no longer is displayed immediately after running a command

The bug

The command block output is no longer displayed after opening a command block right after a command is run. This has appeared within the 1.17 snapshots; this wasn't the case in 1.16.4.

Here is what this looked like in 1.16.4: https://www.youtube.com/watch?v=RJ82G6tbnko

Here is what this looks like in 20w51a: https://www.youtube.com/watch?v=aGqsevVv-8o

Notice how the 20w51a command block needs to be opened twice after the command was run in order for it to display the output. The 1.16.4 command block needed to be opened only once.