Summary:
Compared to other mobs, frogs do not play the walking animation when they take damage. This is also a parity issue, as there is no such issue in bedrock (since version 1.19.10.23 when adding damage animation to mobs https://twitter.com/atorstling/status/1534525221155348480?t=lwhc9b9at9ZSgzm36Bt45A&s=09)
Steps to reproduce:
Place a magma block to prevent the frog from walking.
Summon a frog on him.
Watch the frog take damage.
Observed results:
When taking damage, the frog does not play the walking animation like other mobs.
Expected results:
When taking damage, the frog plays a walking animation like other mobs.
Video:
Bedrock
I can confirm this behavior.