Hello @Nestor Lin ,
Apologies for the delayed response. I checked internally with the engineering team and they confirmed this is excepted behavior. This disablement in the portal is expected as they're planning on integrating the different tools/features within Azure portal experience
Have you tried to manage your record sets and records for your DNS zone by using the Azure portal.
If you're still running into any issues, please send an email to AzCommunity[at]Microsoft[dot]com with the subject ATTN: Grace including your domain, subscription ID and a link to this thread so we can assist you offline.
Thanks,
Grace