stats_clear_data_wipe - to clear all statistics - WIPE.

why does this command also wipes the overall playtime on the server
i have more than 2k Hours on this Server

There is no way this command can clear the all-time stats.

You may have cleared it in another way, for example through the UI

nope i just used the command stats_give_award and then stats_clear_data_wipe

it happend twice to me now

Send me in private messages - all stats data-files, configuration, your SteamID, the time when the Wipe command was executed and the number of players online.