I get log entries that do not happen in Leap 15.5.
searching the internet I found the aur version x11vnc-git 1:0.9.16.r12 it fixed the issue. It appears to be a 6.3.7 and newer kernel issue. I will open a Bugzilla on this. Link AUR (en) - x11vnc-git
Bugzilla – Bug 1213153 Submitted
I think they are mouse movements - that is what is in most of the Debian issues.
08/07/2023 10:38:47 client 1 network rate 35445.7 KB/sec (95144.3 eff KB/sec)
08/07/2023 10:38:47 client 1 latency: 0.7 ms
08/07/2023 10:38:47 dt1: 0.0410, dt2: 0.0465 dt3: 0.0007 bytes: 3090570
08/07/2023 10:38:47 link_rate: LR_LAN - 1 ms, 35445 KB/s
08/07/2023 10:38:47 client_set_net: 192.168.20.101 0.0003
08/07/2023 10:38:57 created selwin: 0x1700040
08/07/2023 10:38:57 called initialize_xfixes()
*** fb_push ublen NOT ZERO: 16311911
*** fb_push ublen NOT ZERO: 1526748927
*** fb_push ublen NOT ZERO: -301943553
*** fb_push ublen NOT ZERO: -1728058381
*** fb_push ublen NOT ZERO: 457704657
*** fb_push ublen NOT ZERO: -205
*** fb_push ublen NOT ZERO: 1208277247
*** fb_push ublen NOT ZERO: 655148
*** fb_push ublen NOT ZERO: 1226440954
*** fb_push ublen NOT ZERO: 1094748757
*** fb_push ublen NOT ZERO: -70254515
*** fb_push ublen NOT ZERO: -49267
*** fb_push ublen NOT ZERO: 1905121
*** fb_push ublen NOT ZERO: 1834029090
*** fb_push ublen NOT ZERO: 1241519162
*** fb_push ublen NOT ZERO: 1230537984
*** fb_push ublen NOT ZERO: 1392507903
*** fb_push ublen NOT ZERO: -16777472
*** fb_push ublen NOT ZERO: 14810963
*** fb_push ublen NOT ZERO: -402849681
user@LLR4:~> x11vnc --version
x11vnc: 0.9.16 lastmod: 2019-01-05