AI Images Not Submitting After Update

If you're talking about the same issue I've had on occasion, I sometimes have to upload the same asset two or three times before it actually shows up under the New tab. Then I delete the doubles or triples. It's a bug, but a rare one.

Please note: there is a difference between uploading and submitting. During the upload phase, you transfer an asset to the Adobe servers. During submission, you submit uploaded assets to the moderation queue. 

There is a general submission limit for assets. But in that case, your submission button is disabled.

Check your settings, especially your browser settings. Either use a different browser, or start the browser without any add-ons. Some add-ons may interact and block part of the Adobe websites.