for those who have the same problems like me while connecting a bluetooth keyboard and a bluetooth mouse at the same time and figuring out lags on the mouse here is a fix for this.
go to your device manager. under network adapters you will find a „broadcom 802.11abgn wireless sdio“ adapter.
at the setting in this adapter go to the rider advanced in the list choose „bluetooth collaboration“. further in the pull down menu go to disabled.
voila now the keyboard and the mouse work like a charm without lags and hangs…