Our host has posted the following message

Event Type: Network Upgrade

We are performing system changes in the Chicago location during the following scheduled maintenance window.

Start Time: 2023-09-12 05:00:00 UTC
End Time: 2023-09-12 07:00:00 UTC

We schedule higher impact maintenance events during off-peak times to maintain our ideal hosting environment. Our engineers make every effort to minimize system impact; however, Chicago instances may be unreachable for some, or all, of the scheduled maintenance window as we perform network, firmware, or host upgrades.