Hi AE. I'm Greg, eleven years awarded MVP, Volunteer Moderator, and Independent Advisor here to help you until this is resolved.
Whenever banks change security it can cause the desktop icon to stop working, So create a new icon from the web page or app as shown here.
https://www.intowindows.com/how-to-create-websi...
https://www.tenforums.com/tutorials/93296-creat...
Are you using the website or the software Desktop available from:
https://www.tdameritrade.com/tools-and-platform...
If you're using the website, try another browser. I would have several browsers on your task bar so there's always one that's best for the task. I use Firefox, Edge and Chrome in that order of preference. It's easy to share bookmarks between all of them in their settings under Import Favorites from another Browser. Firefox and Chrome let you sign in to save and/or sync your Favorites on any other device you sign into, and are more reliable than Edge at doing this. Set the preferred browser as Default in Settings > Apps > Default Apps.
Firefox download: https://www.mozilla.org/en-US/firefox/new/
Chrome download: https://www.google.com/chrome/
If you're using the software then make sure you're following the instructions in the link at top. If it still doesn't work then contact them at the phone number at bottom of page, or use another Contact Us option to get Support included with your account.
I hope this helps. Based on what you report back I can answer any questions and may have other steps to perform. If you'll wait to rate whether my post resolved your problem, I will keep working with you until it's resolved.
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