Depth of field artifacts issue in 4K

Hello everyone, I'm experiencing a problem with artifacts that appears ONLY in 4K with Depth of field. For information, we use Cinemachine for our cameras with a Main Camera that has the CinemachineBrain and each camera has a volume profile in which I put a Depth of Field Override with the use of Physical Camera as the Focus Mode and the quality set to High. This is not for a game, so if it's laggy in the game view it's not a major concern since we render the full sequence in EXR.

Here is what I've already tried to solve the problem :

1- Ticking the checkbox called "Stop NaNs" in the Main Camera options = Problem not solved
2- Changing the AA from SMAA to TAA makes the artifact disapear but creates other problems
3- Same with changing from Forward to Deferred, it makes the artifact disapear but creates other problems

I am stuck with a full pipeline so these two last options are not correct solutions for us.

The only solution I've found yet to make it work, is to identify which object is creating the artifact (because it seems to be object related) and make a very small rotation of 0.01. Like so, the artifact disappears and the object doesn't seem to have moved. This is what I would call a "dirty manual trick" and we have a lot of shots to do, so if we have to do that manually on each shot, it won't be the best approach.

I wonder if any of you here has already faced this issue and if you have any better solution to solve this ?

Find below 2 screencapture of the problem and the solution I've found so far.