subdomain not removed from dns

Greetings:

I have created a subdomain, sub.example.com. It has been added to the dreamhost DNS. Up to now everything was ok. I have then deleted this subdomain but the fact is the entry is not removed from the DNS. When I later tried to recreate my subdomain sub.example.com, I got a message error saying:
Can't add domain: already in our DNS system.

I then checked the DNS and seen that the sub.example.com was in the
Non-editable DreamHost DNS records For example.com

Therefore I am stucked. Is there any way to override this behaviour (should I stay bug?) or should I contact the dreamhost support

Thank you for your help

How long has it been since you deleted the subdomain? It may take a few hours before everything gets cleared up.

Support should be able to delete the DNS record for you if you contact them.

Yes I know that it takes some time to propagate in the DNS but I did it yesterday and the subdomain is still present. I will contact the support to have it removed.
Tkx