Automatic failback of cluster resources after reboot

Hello There,
I have noticed a use case in SLES15 that on a two-node cluster when a node was rebooted, the resources failed over to next node. But as soon as Node1 came up, the resources automatically failed back to node1 .
The resource-stickiness value is 100
Is there any key feature in SLES15 that supports this observation?
If not, what could be the probable reason?

What are your constraints ?
The easiest way is to run :

crm configure show

The most common error is when somebody forgets to clear a location constraint after a resource migration.You can identify this type of constraint from the others by the “cli” inside the name.