Node deactivated from interface


Hello,
I use Radioss for a dynamic impact problem, but also for the moment to validate my model through a quasi-static analysis.
A first component compresses a second component with an imposed velocity. The interface between them is of type 7. In dynamic explicit simulation the interface works fine but in the implicit simulation, I get a warning in interface : 'NODE ... DE-ACTIVATED FROM INTERFACE'. If I make an 'initial penetration' (initial gap < gapmin entered into type 7 interface) I do not get this problem (however I get initial constraints I want to avoid).
Would anyone know what the problem might be ?
Hereunder a part of my engine.out file:
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CYCLE TIME TIME-STEP ELEMENT ERROR I-ENERGY K-ENERGY T K-ENERGY R EXT-WORK MAS.ERR
0 0.000 0.2000E+05 SOLID 39426 0.0% 0.000 0.000 0.000 0.000 0.000
ANIMATION FILE: pression_statique_07A001 WRITTEN
***** WARNING : ELEMENT FORMULATION ISOLID= 0
IS NOT AVAILABLE FOR STIFFNESS MATRIX BUILDING, USING GENERIC ONE INSTEAD
POSSIBLE CONVERGING ISSUE. *****
*--------- STIFFNESS MATRIX SETUP ---------*
SYMBOLIC DIM : ND = 155532 NZ = 2897175 NB_MAX = 26
FINAL DIM : ND = 47480 NZ = 761383 NB_MAX = 26
--STIFFNESS MATRIX WILL BE REFORMED AFTER EACH 3 ITERATIONS--
* CONVERGED WITH 0 ITERATIONS, |du|/|u|,|r|/|r0|,|dE|/|E|= 0.1000E+01 0.0000E+00 0.1000E+01
WARNING INTERFACE 701
NODE 13703 DE-ACTIVATED FROM INTERFACE
WARNING INTERFACE 701
NODE 13548 DE-ACTIVATED FROM INTERFACE
WARNING INTERFACE 701
NODE 13693 DE-ACTIVATED FROM INTERFACE
ANIMATION FILE: pression_statique_07A002 WRITTEN
* IMPLICIT COMPUTATION TERMINATED WITH TOTAL NONLINEAR ITERATIONS: 0
* TOTAL NUM.OF MATRIX FACTORIZATION AND PCG ITERATION: 0 0
RESTART FILES: pression_statique_07_0001_[0001-0001].rst WRITTEN
-------------
** CPU USER TIME **
#PROC [K]SETUP [M]SETUP IMPL.SOLV IMPL.TOTAL
1 .4862E+02 .0000E+00 .0000E+00 .4930E+02
#PROC CONT.SORT CONT. F ELEMENT KIN.COND. INTEGR. I/O TASK0 ASSEMB. RESOL
1 .5591E-01 .6813E-02 .2678E+00 .2133E-01 .4654E-03 .5012E+00 .9117E-03 .1199E-01 .5030E+02
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Thank you a lot,
Kinds regards,
Alice