keyboard and mouse slow to return after sleep or hibernate

i have a lenovo t480 and am running 15.0, using xfce. when the laptop returns from sleep of hibernate the screen comes back immediately but the keyboard and mouse are extremely slow to return to function, taking 20-30 seconds to come back. how do i go about diagnosing this problem and finding a solution. not looking for a particular answer (although I won't say no to it!) but trying to learn how the hibernate/sleep/wake up works in slackware.

thanks
brian-in-ohio