Hi, @the-web-tailor. It appears the time to live (TTL) values on the current DNS record are 86400 seconds (which is 24 hours):
spadeschapelles.be. 86400 IN NS dns1.p03.nsone.net.
spadeschapelles.be. 86400 IN NS dns2.p03.nsone.net.
spadeschapelles.be. 86400 IN NS dns3.p03.nsone.net.
spadeschapelles.be. 86400 IN NS dns4.p03.nsone.net.
Based on this, I’m assuming the previous DNS records also had a TTL of 86400. If so, it may take 24 hours for the DNS changed to propagate. Note, it could be longer as the caching is determined by the previous DNS records (not the current ones). If the previous TTL was higher (which I don’t know because I cannot see what the previous DNS records were), then the delay in changes will also be longer.
There is a support guide with more information here:
If there are still issues more than 24 hours after changing the name servers, please let us know.