Today Xiaomi has rolled out MIUI8 7.6.8 Developer OS update for Xiaomi MI6, which has fixed two issues, one of the issues is that it loads slowly when desktop re-switched on, we highly recommend you to use Xiaomi MI6 MIUI8 7.6.8 Developer OS to download for update.
Fix the connecting stability for some wifi router （06-06）
Fix the issue that the desktop loads slowly when re-switch on. （06-07）
You can download the complete Xiaomi MI6 MIUI8 7.6.8 Developer OS from MIUI official.