DNS error

A week ago, TMD migrated my websites to another server. 

I changed all nameservers according to their new server and meanwhile they are all resolved.

Since then, my sites are generating the error : ERR_NAME_NOT_RESOLVED

Not always and not all at the same time.

Today again, one of my sites cannot be accessed (received several emails from my members).

TMD says there's nothing wrong at their end, they can open the site.

I can't open the site and my members can't either.

What is causing this problem? Is there some file in the script (7.3.3) which is preventing the sites to open?

Can you PM me the website.

Done dolphin_jay

Meanwhile, a second add-on domain fails to open.

TMD is denying any errors, so I can't figure out why this is happening.

Can you post (or PM) the domain and name servers TMD wants them set to?

Parent zone does not provide glue for nameservers, which will cause delays in resolving your domain name.

No nameservers respond to queries via TCP.

No nameservers provided an SOA record for the zone.

No MX records exist within the zone.

Domain has no WWW hostname record.

The domain literal has no address records.

domain does not have an SPF record, nor an SPF formatted TXT record. 

The strange thing is, that this DNS error is only occuring with my websites built with Dolphin 7.3.3

My other websites are opening fine, but they are built with WordPress.

So my logical brain says that this is Dolphin related, since I can open all other websites without DNS error.

For me, this is chinese :-)

Maybe you can explain how to solve this?

The problem seems to be my ISP

I changed DNS to Google DNS and now it works fine. When I finish editing my sites, I change the DNS back to my ISP

It's not the ideal workaround, but as long as they can't solve their DNS server problem, I can still work :-)

I have the same issue what can i done? The ns1 and ns2 is correct. What ISP mean?

ISP - Internet Service Provider

Google DNS: 8.8.8.8 and 8.8.4.4 

Hi AlexT, thanks for the reply.

That solution works perfect!