Issues with Discord links (Patreon)

So, whenever a new subscriber arrives i send them a message with an invite to the Discord server BUT i noticed the links are not working as they should.
Since the server is a reward for the subscription i'm setting the invite to be used only one time, everytime there's someone new i generate a link to send them.
The thing is i noticed that Discord doesn't seem to generate different links everytime, often it just gives me the same link i already sent to someone else and i don't know why.
Are YOU having issues joining the server? If so, let me know, also let me know if there's a way to make this work :/
Thank you in advance!! uwu