Related: World champion Magnus Carlson recently resigned a match after 4 moves as an act of honor because in his previous match with the same opponent, Magnus won solely due to his opponent having been disconnected.
His opponent, Ding Liren, is from China, and has been especially plagued by unreliable internet since all the high level chess tournaments have moved online. He is currently ranked #3, behind Magnus Carlson and Fabiano Caruana.
All professional chess games have a time limit for each player (if you've ever heard of "chess clocks" -- that's what they're used for). In "slow chess" each player has a 2-hour limit and all of the other time control schemes (such as rapid and blitz) are much shorter.
There’s an interesting protocol for splitting a Go or chess game over multiple days so that neither party has the entire time to think about their response to the last move: at the end of the day the final move is made by one player but is sealed, not to be revealed until the start of the next session.
For this to work on an internet competition, the judges would need a backup, possibly very low bandwidth communication mechanism that survives a network outage.
This wouldn’t save any real-time esports, but would be serviceable for turn based systems.