diff --git a/DBSyn/DatabaseModel.swift b/DBSyn/DatabaseModel.swift
index 5f49079..82a9c19 100644
--- a/DBSyn/DatabaseModel.swift
+++ b/DBSyn/DatabaseModel.swift
@@ -902,6 +902,9 @@ final class DatabaseModel: ObservableObject {
                     recordQuery(statement, profile: profile, database: activeDB, succeeded: true, detail: status)
                 }
             } catch {
+                // An old connection must not overwrite the newly selected
+                // connection's state when its request finishes later.
+                guard selectedID == profile.id else { return }
                 status = "Error"
                 result = QueryResult(message: error.localizedDescription)
                 if !listingDatabases {
diff --git a/DBSyn/MySQLProtocol.swift b/DBSyn/MySQLProtocol.swift
index 9993ac5..1a3ece0 100644
--- a/DBSyn/MySQLProtocol.swift
+++ b/DBSyn/MySQLProtocol.swift
@@ -523,7 +523,11 @@ enum NativeMySQLRunner {
         }.value
     }
 
+    // Connection shutdown may wait behind a slow network operation on the
+    // session's serial queue. Never make the SwiftUI main thread wait for it.
     static func disconnect(profileID: UUID) {
-        PersistentMySQLSessions.shared.disconnect(profileID: profileID)
+        Task.detached(priority: .utility) {
+            PersistentMySQLSessions.shared.disconnect(profileID: profileID)
+        }
     }
 }