Hi Andreas,
Thank you for contacting Intel Community.
Generally, the device part number ended with the additional suffix 'TS' is referring to the customer-specific ordering suffix, the material that builds directly for some specific customer request. These are added to the device part number when a device has undergone additional qualification upon request. The default part number would be 5CSXFC6C6U23I7N. You can refer to the date code decoder on how to interpret the general code.
https://www.intel.com/content/www/us/en/programmable/support/quality-and-reliability/decoder.html
Intel PSG has its authorized distributor to sell Intel devices. If the customer got the devices from formal distributors, they shouldn’t worry about the device authenticity as the devices must be valid units. Otherwise, we do not ensure the device quality and do not provide further service. You can find the authorized distributor list from the link below:
https://www.intel.com/content/www/us/en/partner/where-to-buy/overview.html
Thank you
Regards,
Chia Ling