I have an Avocor display which is based on FlatFrog technology. I installed
Debian 11 ISO with Xserver.

While using the whiteboard or paint with pen and finger both, It works for
sometime and then after it freezes. then we need to reset the usb to make
it work again.

in Xorg log file :
[   892.464] (EE) event4  - FlatFrog FlatFrog AE-TK65P-20P1E-M3-007f:
kernel bug: driver sent multiple touch down for the same slot(EE) event4  -
FlatFrog FlatFrog AE-TK65P-20P1E-M3-007f: kernel bug: driver sent multiple
touch down for the same slot(EE) event4  - FlatFrog FlatFrog
AE-TK65P-20P1E-M3-007f: kernel bug: driver sent multiple touch down for the
same slot

Installed input packages are :
ii  libinput10:amd64                     1.16.4-3
amd64        input device management and event handling library - shared
library
ii  xserver-xorg-input-all               1:7.7+22
amd64        X.Org X server -- input driver metapackage
ii  xserver-xorg-input-libinput          0.30.0-1
amd64        X.Org X server -- libinput input driver
ii  xserver-xorg-input-wacom             0.34.99.1-1+b1
amd64        X.Org X server -- Wacom input driver


While debugging with *libinput record*, observe below things:
We were unable to get an event on Xserver after a few minutes of testing.
But at that time we were getting the events in *libinput report *while the
whiteboard freeze.

Attached connected *device list* and *libinput record output*.

Thanks & Regards
Raushan