Unable to sign-in to Premiere Elements 13

The support agent failed to do their job properly.
As said by John T Smith ,  go back to chat and only ask to have your activations reset.

You may also need to install the CC app before reinstalling Premiere Elements, even though you don't use Creative Cloud:

https://helpx.adobe.com/download-install/kb/creative-cloud-desktop-app-download.html

(this is the ONLY support Adobe still offers for old programs)
When you can't properly deactivate a serial number
BE SURE TO ONLY ASK FOR ACTIVATION SUPPORT TO ADJUST YOUR ACTIVATION COUNT
You may need to PERSIST or TRY AGAIN to find a support agent with more experience

Be sure to remain signed in with your Adobe ID before accessing the support link
Do be aware that Adobe's staffing is impacted by the virus, so wait times are long
-you MUST make sure that your browser does NOT block ads, scripts, or pop-ups
-you MUST also allow 'cookies' in your web browser for the support link to work
This link will go directly to the chat option
Type "Agent" in the chat box to bypass the chatbot and be connected to a person
-Meaning type in the word Agent without the quote " " marks
https://helpx.adobe.com/contact.html?rghtup=autoOpen
- or by telephone https://helpx.adobe.com/contact/phone.html
.
Adobe does NOT do support by email, so beware of answering anyone who sends you a private message
-click for more information about scammers https://tinyurl.com/10791730