When you access Aria operation for logs UI from VIP IP/FQDN you see the page not responding intermittently.
Aria Operations for logs 8.x
Undersized Aria Operations for logs cluster
Please review Sizing the VMware Aria Operations for Logs Virtual Appliance documentation and verify if your events per seconds rate is matching the correct size of the cluster. Add more nodes or increase size as required.
Please refer to Cisco ACI based environment conflicting with the VIP in Aria Operations for Logs document and disable data plane learning. Please refer to Configuring Dataplane IP Address Learning per Endpoint Using the GUI section of the official document.
In the newer Cisco ACI version you can configure an endpoint and treat it as a virtual IP address as shown below.
Its a requirement to have the nodes on correct size to prevent performance issues form happening like UI not available or ILB/VIP going down.