MarleyI noticed that #Proton Onion Site seems to be mostly down the last few weeks, either very slow to load or simply timing out the connection. Is this a known issue?
Xavier Ashe 
@marley @protonprivacy It took me a few tries, but it finally pulled up for me.
https://protonmailrmez3lotccipshtkleegetolb73fuirgj7r4o4vfu7ozyd.onion/
Proton@marley Some things you could try to troubleshoot this on your end is to generate a new circuit or new identity in the Tor browser for our website, or set the Security level in your browser to Standard instead of Safer or Safest to see if this helps. If you're using any extensions/javascript blockers etc. try disabling them and see if there's a difference.
Thanks for the answer. It works sometimes but not reliably (recently it has failed to load more often than it has loaded correctly) and I usually notice that if the onion site doesn't load, even after trying a new circuit, the clear-net site still seems to be up. I don't use extensions not already included with the Tor browser and scripts are not blocked. Proton normally works for me at the Safer level in the Tor browser, is there a reason why Standard would be better? Is the onion site loading reliably for you on your end?
@marley Yes, it's loading reliably (on Standard security). On Safer, additional blockers may be active in the browser which may result in slower loading times (or timeouts).
Additionally, if you're using a VPN, this may also be the cause of the connection instability/slowness.