Plugin instructed the server to rollback the current transaction

[Krishnadas K P]

I have a 3 node MySQL cluster with group replication enabled. I am using MySQL version 8.0.39-0ubuntu0.24.04.2. I have setup the replication in multi-primary mode. However, my application is only connecting to one node and reading and writing from/to that single node. The rest of the 2 nodes are just replicating data and ready to serve writes anytime I point my application to it. This cluster works most of the time but when I apply large load to it, a number of transactions fail with the message "plugin instructed the server to rollback the current transaction". On reading about this, I could understand the issue can arise due to conflicting writes in multiple nodes. However, in my current setup, write is ONLY going to one node. There should not be a conflicting write from another node. When I change the setup to single primary, this error disappears. How do I solve this issue ?