Thanks for the tips.
I did see that the web address resolved to DH ns servers, in fact both the with and without www resolved. The problem solved itself and was apparently a problem with my ISP’s DNS cache that took too long to update. When I VPN’d into a server I have elsewhere, both versions displayed with no problem.
It took >24h though, which is a lot more than I had ever had to wait for a DNS to propagate, but to be fair, it does say that you have to wait up to 48h, but I always assumed this was an exaggeration.
(Mantra #248: DNS is not for the impatient)