Problem with Associate Elastic IP Address

I confirmed that even if multiple private IP addresses are set for one ENI, the private IP addresses are listed as shown in the image below.

It is displayed normally in my AWS account, so there may be some kind of UI bug.
In the case of a bug, it is not possible for the user to deal with it, so it is necessary to open a case with AWS Support under "Account and billing".
Inquiries under "Account and billing" can be made free of charge.
https://docs.aws.amazon.com/awssupport/latest/user/case-management.html

By the way, can I check CloudTrail's event history to see if any errors have occurred?
https://docs.aws.amazon.com/awscloudtrail/latest/userguide/view-cloudtrail-events-console.html

Hello.

Just to be sure, are you saying that multiple ENIs are successfully attached to EC2?
My AWS account successfully lists the private IP addresses attached to EC2.
There may be a problem with the cache, cookies, UI, etc., so please try using an incognito browser or try the settings from another browser.

I do not see any new private IPs in the list as you are able to view. I have tried multiple browsers and different devices and this issue is persisting for me. I have tried several EC2 instances but cannot get more than one IP to show any more. My existing EC2s used to show these IP addresses earlier, any new IP I add on those servers also don't show up. This is why I am thinking this might be some sort of limit issue in AWS.

As you can see I only see one IP here whereas the EC2 instance has multiple IP addresses.

Do I need to create a separate ENI for each private IP address or would it accept multiple IP address on a single ENI? I used to have multiple private IPs on a single ENI and that used to work, not sure if this was changed recently to allow only one private IP per ENI available for the association.