Extreme Local Coop Lag / Rubber Banding

Experiencing extreme rubber banding and lag-like performance in couch coop on PS5.

Steps I took to reproduce:

  1. Purchased/Downloaded Diablo 4
  2. Created Blizzard account - linked to PS account
  3. Chose Druid / created character
  4. Started Prologue
  5. At very start of Prologue, had Player 2 join via 2nd controller
  6. Player 2 linked their Blizzard account and created a Sorcerer
  7. Didn’t notice any problems for the first 30 seconds or minute or so
  8. As we walked around, very quickly started noticing characters bouncing around the screen (rubber banding).
  9. Talked to NPCs and kept experiencing the same lag and rubber banding

Troubleshooting Steps attempted (nothing worked):

  • tried disabling cross-play on both characters
  • tried Player 1 as a Rogue and as Sorcerer to go with the Player 2 Sorcerer
  • tried disabling some of the online features we could see

Searched around online and found no solutions. Couldn’t get a refund from Sony, since it was a downloadable game.

I did hear one person with this issue that solved it by switching from WiFi to wired ethernet, but I do not have the ability to do this due to where my ps5 is located. I also do NOT have any lag or internet issues whatsoever on any other games. Find it “hilarious” that the only lag issues I’m having is on a LOCAL coop game that I have no desire of any internet features for.

Appreciate any help, or if this can be fixed as it’s unplayable in the current state.

Edit:
I think I figured this out… The game auto-launches the “basic” half download version, which has an old rubber banding/lag bug. If you close and restart, you get the patched version that seems to work (so far).

Same issue here still.
When player two joins and attacks, it’s like they attack a second later and the screen stutters with every attack or ability.
Literally it’s unplayable. It has been like that since released.
No connection issues with anything before, playing on Xbox series s and having ethernet connected.

Its been like this for months. Blizzard seems to be ignoring this issue and most likely is being caused by the game being in online mode online with no fix except to have an offline mode coop.