Update June 2nd 2020. We've noticed that we are having some difficulty connecting to Roblox and thing that for some users at least Roblox is down or unreachable for some players.
Taking a look at Down Detector confirms this:
https://downdetector.com/status/roblox/.
Some people are reporting:
'Server contentions (Error Code 227)'
There are a few resources to try fix error code 227, we've not tried them ourselves as we don't have this particular error: How to Fix Error Code 227
According to another site Roblox may be up but just not unreachable for some people:
https://www.isitdownrightnow.com/roblox.com.html
There also, people are reporting connetion issues despite the site being up.