Mixer stops when shifting from 10 down to 8

Classic Model # k45ssac It works fine in the lower gears. If I get to 6 too fast, it stops sometimes. If I get to 10 and shift it down to 8, it stops. It turns back on at 4. Sounds fine, speed tested in all gears.

crwdns2893858:0crwdne2893858:0 crwdns2893862:0crwdne2893862:0

crwdns2894050:0crwdne2894050:0

crwdns2889612:0crwdne2889612:0 0
crwdns2892346:0crwdne2892346:0