That's helpful to know. Thank you. Any advice on what I have to fix on the network?
Unfortunately that is a very wide field. If it was me, I'd start by going into the modem/router, and see if they received a connection-loss or restart. If they did, you'd need to speak with your ISP to resolve the connection issue.
If you have a consumer grade standalone 'home router' as well as a separate modem, make sure it did not crash and reboot at that time. High-throughput constant-throughput connections can overwhelm some less-well-designed units' network buffers over time and cause a crash.
But there are a LOT of things it could be, up to and including the remote server simply dropping the connection (which would need Facebook support to fix). Step one is to figure out where the connection is actually dropping.
It could be:
-Your computer's NIC having a problem
-The cable from your NIC to the switch (if equipped)
-The switch (if equipped)
-The cable to your router
-Your router (if equipped)
-The cable between your router and modem
-Your modem
---(Stuff you can fix yourself ends here)---
-The connection between your modem and the local concentrator
-Your ISP's intranet link
-Your ISP's backbone uplink
-The backbone link to the local downlink
-The local downlink to the local intranet
-The intranet connection to the ingest server
-The ingest server itself
Cables tend not to have an intermittent fail like this, but should not be forgotten-about. Switches generally don't have internal logging unless they're managed switches, which are VERY uncommon in home setups. Routers and modems tend to have internal logging, but a lot of the time it's cleared on reboot, so you'd be looking for a log-start around the time your connection came back, or an entry specifying a connection loss or system startup at that time. If it's a connection loss from the modem, that'd be something to talk to your ISP about.
Unfortunately, as noted it's a VERY wide field to troubleshoot.