When a command block contains a command to clone itself into a new location, the command re-triggers indefinitely, executing the clone over and over again. This occurs in 1.18, but not in 1.17.

Reproduction

1. Place a command block
2. Type in the command 

   clone ~ ~ ~ ~ ~ ~ ~ ~2 ~

3. Place a button on the command block
4. Press the button

Expected Outcome
The command block is cloned with the command two spaces above the original block.

Actual Outcome
The command block is cloned infinitely upwards every other block (see screenshot).