Polar bears can hit / attack players through blocks

I have the same issue, especially polar bears with cubs. Not just glass panes but also solid blocks.

Polar bears can even hit players swimming under frozen oceans.

Trying to hide in a thin house but the bear still hits through the back of the wall. It’s okay that the bear can hit the player’s feet through an air block while the player’s head block is covered by a block in front of them (swiping underneath). Why it attacks without access, I don’t know.

oh so this problem has been happening for years- I just reported this

The attack range of polar bears is indeed outrageous, even larger than that of iron golem. If command blocks are used to make polar bears and iron golem attack each other, and then mining cars are used to fix them, with a wall in between, polar bears can easily attack the iron golem, while the iron golem have no ability to return and can only be passively beaten.