Can't confirm, have been running stuff on Hetzner for almost 10 years. They will indeed auto-block you if any application is spamming the private subnet - happens e.g. with IPFS running in its default config. But this always comes after warnings and with an exact explanation of what happened (log of IPs the server attempted to connect to, timestamps etc). I always found support responsive, even in the middle of the night. It may be that I was lucky all the time, despite interacting with various support staff in various of their data centers. Or it may be that your issues had other reasons...