This is not a bug. The email templates for first login and/or password reset are disabled in your portal.
How to fix
Go to Communications → Automation Lists.
Find and enable these templates:
New account created (sends the first-login link)
Forgot password (sends the reset link)
Save, then perform a quick test with a member (create access / use “Forgot password”).
Tip: Confirm the member’s email address and have them check Spam/Junk if the message isn’t in the Inbox.
Quick workarounds
From the member profile, set a temporary password and share it with the member (if your policy allows).
Ask the member to retry Forgot password after the templates are enabled.