Hi Rahul,
Could you please also check the following?
1. whether filters in tcode R3AC1 are maintained correctly.
2. please check ERP table TBE31 whether the following entry exists:
00001321 BC-MID PI_BP_CUSTOMER_BTE_1321
3. The FM in note 757955 should be registered in CRM table CRMC_BUT_CALL_FU.
4. If you want to replicate ERP customers to CRM BP, please check the account group mapping in ERP tcode PIDE.
5. please also check Bdoc in CRM tcode SMW01 whether there are errors
6. whether any queues are failed or locked in SMQ1 and SMQ2.
Best regards,
Ellen