Bad calculated ratio at lower level matrix

Hello all, 

I have created this mesure and i'm triying to use it in a matrix, ratio by etablissement and total ratio are right. My problem is that the ratio by department is not calculated in the rigth way. 

In my Matrix "etablissement" is the first level and "departement" my second level. 
See in the picture what I get (left) by département and what I should obtain (right). 

And here my measure, what should I do to correct this? 

My two table have a relationship many to many

Thanks in advance

Prorata etablissement et departement = 
VAR Etablissement = SELECTEDVALUE('Plan'[ETABLISSEMENT CONSO]) 
VAR Departement = SELECTEDVALUE('Plan'[DEPARTEMENT]) 
VAR CurrentMonth = "202405" -- Remplacez cette valeur par le mois courant si nécessaire 
VAR Numerator = CALCULATE( SUM('Plan '[Nb Heures Catalogue]), ALLSELECTED(FTEHC[AnnesMois]) ) 

VAR DenominatorPerEtablissement = CALCULATE( DISTINCTCOUNT(FTEHC[ID]), FILTER('FTEHC', FTEHC[AnnesMois] = CurrentMonth && 'FTEHC'[Position lieu_2] = Etablissement) ) 

VAR DenominatorPerDepartement = CALCULATE( DISTINCTCOUNT(FTEHC[ID]), FILTER('FTEHC', FTEHC[AnnesMois] = CurrentMonth && 'FTEHC'[Departement OM] = Departement) ) 

VAR DenominatorTotal = CALCULATE( DISTINCTCOUNT(FTEHC[ID]), FILTER('FTEHC', FTEHC[AnnesMois] = CurrentMonth) ) 

RETURN 
SWITCH( 
TRUE(), 
ISINSCOPE('Plan'[ETABLISSEMENT CONSO]), DIVIDE(Numerator, DenominatorPerEtablissement), 
ISINSCOPE('Plan'[DEPARTEMENT]), DIVIDE(Numerator, DenominatorPerDepartement), DIVIDE(Numerator, DenominatorTotal) )