Hello Rob,
I understand you have recently added MX records and TXT verification to use in your domain's DNS settings for Gmail with G Suite. So far I checked there is nothing on our end is blocking, I can see both MX and TXT records.
I used Google dns server 8.8.8.8 (is the primary DNS server for Google DNS) to query (dig) :
; <<>> DiG 9.10.3-P4-Debian <<>> MX mavyn.ai @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32967
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;mavyn.ai. IN MX
;; ANSWER SECTION:
mavyn.ai. 3599 IN MX 1 aspmx.l.google.com.
mavyn.ai. 3599 IN MX 5 alt1.aspmx.l.google.com.
mavyn.ai. 3599 IN MX 5 alt2.aspmx.l.google.com.
mavyn.ai. 3599 IN MX 10 alt3.aspmx.l.google.com.
mavyn.ai. 3599 IN MX 10 alt4.aspmx.l.google.com.
; <<>> DiG 9.10.3-P4-Debian <<>> TXT mavyn.ai @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 65315
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;mavyn.ai. IN TXT
;; ANSWER SECTION:
mavyn.ai. 299 IN TXT "google-site-verification=7ZQUxOtrqgzMVuRtGZYrpUPjbXLM0fJcMtvJOhq3bGs"
;; Query time: 12 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Oct 03 20:23:07 UTC 2019
;; MSG SIZE rcvd: 118
These records are specifically what they should be as per this document[1]. So, it appears some MX and TXT records have been added successfully but you need to check if these records are correct or. If not, I would recommend to reach out to the GSuite support team to get further assistance.
However, If you are using Google Cloud Platform with Google Cloud DNS, you can check the available records against your DNS name from cloud DNS page in your project console. If you require to add, delete or modify the record, follow this article[2], make sure you set the resource record type accordingly.
[1] https://support.google.com/a/answer/174125?hl=en.
[2] https://cloud.google.com/dns/docs/quickstart#create_a_new_record