We are currently in the process of building a cloud service and we are having DNS issues.
DNS is resolving correctly via - Cellular/LTE/Verizon - Wifi/Cable (tested with different ISPs)
DNS is not resolving via cellular/LTE/AT&T
Edit: Problem occurs with iPhone on AT&T/LTE. Verizon works fine, also on iPhone. The problem was reproduced with Chrome + Safari, also after flushing the DNS cache (airplane mode on + off). Chrome on iOS shows the error: ERR_NAME_NOT_RESOLVED, Safari shows not detailed information.
Edit 2: I unfortunately can't share uncensored DNS settings but perhaps that helps (these settings have been up for over a week and the TTLs have not been changed):
A @ <censored ip 1> 600 seconds A sub1 <censored ip 2> 1 Hour A sub2 <censored ip 2> 1 Hour CNAME ftp @ 1 Hour CNAME issue @ 1 Hour CNAME mail @ 1 Hour CNAME smtp @ 1 Hour CNAME sub3 @ 1 Hour CNAME www @ 1 Hour CNAME _domainconnect _domainconnect.gd.domaincontrol.com 1 Hour Edit MX @ mail.domain.tld (Priority: 0) 1 Hour Edit MX @ smtp.domain.tld (Priority: 10) 1 Hour Edit TXT @ google-site-verification=<censored key> 1 Hour Edit TXT @ v=spf1 a mx ip4:<censored ip1> ~all 1 Hour Edit TXT selector._domainkey k=rsa; p=<censored key> 1 Hour Edit TXT _domainkey o=~; email@example.com 1 Hour Edit NS @ ns47.domaincontrol.com 1 Hour NS @ ns48.domaincontrol.com 1 Hour
Do we need to add more name servers or is it a different issue?