The bug

The command block does not output some execution results into chat bar.

For example, use a command block to execute

/time query gametime
or
/ data get entity @p

There are no results in the player's chat bar, the results only can be viewed in the command block.

There is no such problem in 1.12, starting from 1.13.

One effect is that we cannot use the command block to test the timing of redstone circuit, because the message of time query doesn't display in chat.

How to reproduce

1. Ensure the gamerules commandBlockOutput and sendCommandFeedback are enabled:

   /gamerule commandBlockOutput true

   /gamerule sendCommandFeedback true

2. Enter the following command into an impulse command block:

   /time query gametime

3. Activate the command block
   → No message is displayed in chat

Expected behavior

The following message should appear in chat:

[@: The time is ...]

This was the observed behavior prior to 1.13.