Password reset says "key is invalid"

Hello. I imported 1200 users using your plugin. The import worked fine, but we elected NOT to send them the notification email with their username and password because most of them were old users that are no longer active on the site. For users who are active, we directed them to use the Lost Password form to recreate their password. However, when they get the password reset link and click it, it says “Password key is invalid”. This only happens to users who were imported with your plugin. Regular users can reset their password with no problem.

Do you know why this happened, and is there any way I can fix it?

https://wordpress.org/plugins/import-users-from-csv-with-meta/