SG300 & CISOC 3850 port flapping issue

You very possibly have a loop or misconfigured port channel.  
Do both ports 19 and 20 connect to the SG300? Can you post the config of those twp ports?

Any chance that 'port Gi1/0/19 and port Gi1/0/20' are connecting to wifi access points down the line?

yes we added new six Wireless access point to vlan 220  
also we discovered that some cables are faulty plz check the attached snapshots pictures
cable-issue.jpeg
port-flapping.jpeg

also how can i track this mac address that may cause the loop

as you know the L2 loop can happen because of the following 3 issues
1- layer 1 issue cables ,wireless
2- wrong configuration of  port-channel  or setup of the switch configuration
3- STP issue

Kindly check the attached picture is this cable has any faulty issue or its ok .
WhatsApp-Image-2019-11-05-at-9.24.3.jpeg

I wouldn't particularly trust the cable testing features of these switches. The 106m distance to the fault seems unlikely as well, you should have more than 100m cable runs on copper to begin with.

As for the MAC flapping, it's likely clients bouncing between access points, typically on the coverage boundary two access points.
Based on the MAC address OUIs they are Macs or iPhones and some LiteOn device, possibly Android or windows laptop.

Ok thanks a lot your answer explains a lot to me .
My last question  port flapping  between wireless access points is a normal process happens and the switch will creat a  log record for that
Correct