The Flash from Earth-3 is fighting the Trickster when Barry arrives to ask for advice on Savitar in episode 3x09 “The Present”.
Source: What's Filming — Twitter
Central City Bank
Neil Borman is signing up for a new account at the bank and the teller and patrons collapse as he is leaving in episode 4x10 “The Trial of the Flash”. A bank robber with fire powers is robbing a bank when when his powers suddenly shut off in episode 4x16 “Run, Iris, Run”.