My apologies, but I don't believe I should have to use VPN for software downloads.
Well, you should.
A VPN is one of the most useful tool you can have in your PC. The internet is more complex than it seems and, sometimes problems can't be solved by the site you are connecting to.
A real world example: sometimes I need to connect to a website that hosts a remote database but, if I do it using my normal connection (which works everywhere else), the response time is incredibly slow. That's because to reach the server, it takes a route that passes through some hosts that don't work well or don't even respond, so it tries different routes adding so many hops to it. It does manage to connect, but it's very slow, with a latency that is not usable to do actual work.
I tried everything with customer support of that site, they couldn't reproduce the problem and nobody reported it before. So, as a last resort, I tried a VPN and, like magic, even if I used a VPN node in the SAME country I'm in ( Switzerland ), just because there was a VPN in between, it took a very different route to reach the server, and instead of minutes of lag, pages loaded instantly.
You don't have to keep using the VPN constantly, just turn it on when you need it.
My concern is that this is a symptom of a missing TLS security certificate
Surely not, considering you are not downloading from our server directly, but from Cloudflare, and I can assure you SSL/TLS are both enabled on our domain.