Zero X2 handover attempt ZTE to Huawei

Hello All.
There’s zero X2 handover attempt between ZTE to Huawei.
S1 handover are successful.
What can be the cause?
Huwaei to ZTE X2 is successful.

At ZTE basestation Huawei might not be configured as X2 neighbour or X2 handover at all disable on ZTE.

Thanks @Tech_Playon.
It’s configured.

Check MSC definition on BSC route and inter MSC definition shd exist. Also check CRC/device numbering values.

Handover priority.
Could be set to S1 only or S1 priority.

1)Check if both sites MME ip is pingable.
2) check SCTP Port configuration
3) check from signalling trace if ZTE is sending HO preparation request to Huawei
4) on the same time check from Huawei tracing if its receiving HO request.
5) check the reason of X2 failure like it can be target unknown (both sites in different mme)
6) both sites S1 link on same MME