Fortigate S2S IPSEC tunnel Continous flapping with SAP cloud

We migrated the FW from SonicWall to Fortigate 201G  after completing all configuration it’s working fine but the SAP tunnel having issue on migrating time we resolved it, but after 1 week facing flapping issue continously . Using ikev2 and pfs disable as recommended by SAP cloud.

Also we are using separate subnets in phase2. Attached VPN logs.

Our device Fortigate and SAP device Cisco ASA 

Kindly recommend if any things need to be check on Fortigate.

current version fortiOS v7.4.11 build2878 (Mature)