Ensure your Dolphin settings are optimized for your hardware. Generally, you want "Poll Controllers at Startup" enabled to reduce input lag. A Note on "Scrubbed" vs. "Clean" ISOs
The global competitive scene—and more importantly, the Slippi matchmaking platform—exclusively uses Version 1.02. If you try to use a 1.00 ISO, your game will likely desync or fail to load entirely during online play. The Role of Slippi and Emulation 1.02 ntsc ssbm .iso
Head to the official Slippi website and download the launcher. Ensure your Dolphin settings are optimized for your hardware