Plesk Droplet with DO DNS having shenanigans

I’ve setup my Plesk droplet and used the Digitalocean DNS integration to run the DNS through DO.

For new domains, this has worked in the last weeks. However, today I’ve been trying to move existing domains over, and strange things have been happening. Things like adding the mail accounts to Google Workspace is impossible because the connection times out, to a squarespace domain stubbornly stating my old DNS records, while it’s been 72 hours. When I test the DNS records with Google Dig, it might show the old records on one instance, and after refreshing showing the correct ones, only to revert back seconds later.

I’d like to keep my sanity, and first check if this is correct:

• The public ipv4 is 178.128.252.39

DNS records in Plesk:

In Digitalocean, it’s the following (after sync):

I don’t fully understand the NS to IP records in Plesk, or why it has different NS records in Plesk than DO, but it’s setup exactly according to the how to guide. Is this the right result?

Now, in addition to those records, for this site the hosting is done by Squarespace. I’ve removed the following DNS records from Plesk:

I’ve inserted the ones from Squarespace:

Now, I’ve been trying to have an email from this domain, that I created in Plesk, to be added to a gmail account through pop3/smtp. It gives “connection timed out” errors and “cannot find server” errors. I’m setting it up with the mail server being “domain.com”, through pop port 995, which are the details that Plesk gives you. I’ve also tried mail.domain.com, the IP itself, with/without SSL, you name it.

Strangely, Google (and squarespace) seem to have trouble with my DNS records. But when I try the Google Dig tool, it shows all the right records some times, but when I refresh my page it might show all the wrong (old) ones.

Squarespace is the same. It might find the Squarespace WWW Cname one time, and the default plesk WWW cname the other.

I understand propagation takes time, but why can it go back and forth from the right records to the wrong ones, without me doing anything in the meantime?