I’ve recently joined a new team and I have to connect to a Postgresql DB deployed on AWS RDS.
Everyone in my team manages to access it with their chosen OS, VPN (openVPN or AWSVPN, both work with the exact same config file) and DB tool (DBeaver, PGAdmin, other) and they are using the aws endpoint as the hostname which looks like appdata-dev.xxxxxxxxxx0f.eu-west-2.rds.amazonaws.com

I am working on Windows 11 and using PGAdmin4 and OpenVPN (with the same config file as my colleagues). When I add a new server in PGAdmin and fill in all the details, the connection fails with this message:
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However, when I provide the DB IP instead of the endpoint string as a hostname, it connects perfectly:
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This is not specific to PGAdmin, I have also tried with DBeaver and Azure Data studio and I get the same result.
I also have the same result in my backend services which require a connection to this DB (with the hostname and other details provided in my env/config file, it fails when the hostname is the endpoint string but it works when I change it to the IP)
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To resolve the issue, I’ve tried setting the DNS addresses (IPv4) manually on my wifi and VPN settings with 8.8.4.4 / 8.8.8.8 (which was enough of a fix for some of my colleagues on Linux), but it doesn’t seem to fix anything for me.
My ISP is Virgin media and I have a Hub 5 router, but I don’t think that’s the issue because I’ve tried it on other networks (mobile tethering and other wifi), and it still didn’t work.

I know for sure that there’s nothing wrong at AWS level because all my other colleagues can access it fine and we have the same profile settings and permissions on AWS. The RDS also doesn’t have specific whitelisted IP addresses.

The only difference that could potentially be relevant is: out of the people using Windows, I am the only one using Windows 11, my colleagues are on Windows 10 and have no issue to connect to it.

At this point, I don’t know where else to look… 🙁
If anyone has a suggestion, I’d be so grateful!!