Set the Frame Rate to Extreme, 90, or 120 FPS, or as high as your device will let you, and then restart the game to lock it in.
Stop anti-aliasing, shadows, and "Auto-adjust graphics" so that the frame rate doesn't drop quickly.
Fix resources that aren't working right and storage that's full: from the login screen, tap Repair, free up some room, and reinstall if necessary. These are the steps Krafton takes to fix lag and lost links.
Use 5 GHz Wi-Fi (less interference, lower lag), sit close to the router, and stay away from VPNs during games to make your network stable.
If the Wi-Fi signal is weak, try strong 4G/5G or a good hotspot with few devices linked.
To stop thermal slowdown on an Android phone, turn on Game Mode, turn off Battery Saver/Auto-Sync, close any apps that are running in the background, and keep the phone cool. With these changes, the game runs smoothly on all devices.
Do you have another way to solve it? We'd love to hear from you in the comments.