iRule to handle PSH flag segmented TCP packets

Hi

We have the following scenario:

Client app is sending a HTTP auth request to a VS

We have a custom iRule on the VS to intercept the auth request with JSON body containing the username/password to do perform certain actions.

The client sends the auth request in TCP fragments with the PSH flag on the first segment, as a result, the iRule responds to the first TCP fragment where the HTTP request is without the body (username/password) and cannot authenticate it.

I've tried looking at various ways to workaround this with TCP in irules but cannot see if this is possible.

Can anyone assist in pointing me in the right direction? I looked at using https://clouddocs.f5.com/api/irules/TCP__option.html but not sure how to make it work.