I was invited to join a Team today, received an email and accepted but nothing happened. The website opens on my feed, after accepting the invitation and no Teams appeared in my profile. Also who invited me didn't receive my confirmation.
Can it be something incorrect in my profile settings?
Are you two in the same country?
Try clearing the cache of the browser , sometime it can help.
if not open ticket with support
go to this page https://support.upwork.com/hc/en-us
On the bottom click contact support