I refreshed the page and after the second refresh, I got the following message from cloudflare.
The owner of this website (
www.viabtc.com) has banned you temporarily from accessing this website.
I've seen that too, it only took a few refreshes. But somehow it's not stopping the bots.
For now,
it looks like the spammers all go for 23 sat/vbyte, and anything above 30 sat/vbyte has a reasonsable change to get confirmed. Anything under 23 sat/vbyte is futile, and will very soon be low enough to be dropped out of (most) mempools.