Issue with /INTER/TYPE2 and degenerated BRICK user elements

[GeoffreyG30]

Hello,
I am working on a composite laminate simulation in OpenRadioss.
Each ply is meshed with elements oriented along the fiber direction. To model a ply, I use two different types of user-defined elements through USER Property:
• "standard" custom elements representing the bulk of the ply,
• smaller custom damageable elements inserted between the standard elements to represent crack initiation and propagation.
As a consequence, the meshes are non-conforming between plies.
To connect the plies together, I currently use a /INTER/TYPE2 tied interface with SpotFlag = 0 (kinematic tie). However, the results show non-physical behavior, in particular abnormally high stress values in some elements.
At this stage, I strongly suspect that the issue may come from the combination of:
• the use of degenerated BRICK user elements (8-node elements where only 4 nodes are effectively used to represent shell-like behavior),
• and the use of the TYPE2 tied interface

In other words, although the elements behave as shells in the formulation, they are still interpreted by Radioss as BRICK elements, and I am not sure whether the TYPE2 interface handles this situation correctly. In particular, I don't know how the type 2 contact has access to the correct shape function if Radioss sees BRICK element.
I would appreciate any suggestions regarding:

1. The best way to connect non-conforming composite plies in OpenRadioss.
2. Whether /INTER/TYPE2 is robust and recommended for interfaces involving degenerated BRICK user elements behaving as shells.
3. Possible alternatives that could improve load transfer between plies while avoiding numerical artifacts (e.g. mortar, alternative tied formulations, or cohesive approaches).
4. Any known limitations when combining TYPE2 interfaces with USER Property / USER-defined elements.
   Thank you for your help.

[GeoffreyG30]

Additional observations after further investigation:
I examined the tied contact forces generated by the /INTER/TYPE2 interface and they appear to be excessively large, even at the very beginning of the simulation. These large tied forces seem to correlate with the abnormally high stress values observed in some elements close to the interface.
As a comparison, I ran an equivalent model where the plies are connected using merged nodes instead of a TYPE2 tied interface. In that case, the abnormal stress concentrations do not appear, suggesting that the issue may be related to the tied contact formulation rather than to the element formulation itself.
This leads me to wonder whether the computation and redistribution of tied contact forces from the secondary nodes to the master elements could be responsible for the observed behavior.
More specifically, my USER elements are implemented as degenerated BRICK elements with a plate/shell formulation (only four nodes are effectively used). I am therefore questioning whether /INTER/TYPE2 correctly handles this type of element during the tied force computation and force transfer process.
Could there be any limitation or known issue related to the use of TYPE2 interfaces with USER-defined degenerated BRICK elements behaving as shells?
Any insight would be greatly appreciated.