I click on the BW button, choose an option, and I get the error “Unable to auto-fill the selected item on this page. Copy and paste the information instead.”
This is why it doesn’t work, they’ve made the username something no password manager would recognize. Normally it would be id=“username” or similar.
I would normally recommend adding usaa-form-v5-7-5-input-3wdt4o8crxh as a custom field but it looks like this ID name will change often so that would be pointless.
Sorry, but it looks like copy and paste is the only option until the website uses standards that almost every website uses. I have a feeling they did this on purpose but who knows?