Entity targeted by frogs and axolotls can't be detected by /execute on target

Summary:
Frogs and axolotls don't target the entity they want to attack.

Steps to reproduce:
frog:

1. Get a spawn egg using:

   /give @p slime_spawn_egg{EntityTag:{Size:0}} 1

2. /setblock ~ ~-1 ~ repeating_command_block{auto:1b,Command:"/execute as @e[type=minecraft:frog] on target run say hi"}

3. Spawn a frog.
4. Spawn the small slime.

axolotl:

1. /setblock ~ ~-1 ~ repeating_command_block{auto:1b,Command:"/execute as @e[type=minecraft:axolotl] on target run say hi"}

2. Spawn an axolotl.
3. Spawn a drowned/tropical fish.

Observed results:
The message "Hi" does not appear in the chat.

Expected results:
Frogs and axolotls will target an entities and the message "Hi" will appear in the chat.