That falls off long before it gets to our subnet. So, it can’t be us blocking you.
But, you’re not the first person to have trouble…though, I think last time it sorted itself out after a few hours.
Here’s what you can try (but read to the end, as there was a reason I took this other mirror offline):
Edit your hosts file, and add 149.28.242.101 software.virtualmin.com
Then try pinging/tracerouting again, and then if it all works, go ahead and try the install.
Don’t forget you did this. Having hard-coded IPs is a bad thing, and I make no promises that this address will work beyond the next few days (though it probably will).
This is our secondary repo mirror, that I took offline a while back as it was causing troubles with yum/apt metadata mismatches, and I never figured out what was going on, so I disabled it.