[Obm] Contact Deletion ok on OBM but nok on phone

[Benoit CROQUIN]

Hello,

The following problem we face concerns a no-synchronization between obm and phone devices.
We can not understand why when a contact is delete via obm interface, the contact is still present in phones.

I have checked opush.log file (in /var/log/opush) and find some errors : 

15:57:09.784 [ERROR] {o.o.p.s.e.CacheEvictionListenerImpl} [t15/cSync/r211520/my.name at company.fr] Eviction detected on cache unsynchronizedItemService for key Key_2_4_2_4{syncKey=SyncKey{syncKey=e65ab1bc-3687-46ee-8b61-3ed5240aa7fc}, unsynchronizedItemType=DELETE}

Is this error relevant ?

Could you tell me please why contact deletion in obm is not synchronized with phones ?
I also have to check if every phone device is well synchronized, so is there a way to know from obm server what contact are on phones ?

Thanks in advance,

Benoit Croquin