Bluetooth Stylus & Mouse lag

Have only just purchased an XPS15 (Series 7590) running Windows 10 & my Wacom Intuos tablet performs noticably worse than it did on my previous 10yr old Toshiba latop, tiny bit laggy around menus for example and when drawing (which is what I bought the XPS specifically for).

When I use a bluetooth mouse at the same time the stylus is absolutely unusable, about a second behind gestures, very slow.

Have disabled Windows Ink and made all the suggested adjustments to Wacoms settings to improve performance, updated drivers etc. all to no avail.

I always understood one can use up to 3 devices via bluetooth without any slow-down (however the lag is noticable on the XPS 15 even with 1 device - the stylus).

Is there something simple I am missing?

Many thanks!