Hi @G_Willi_HAMMER_TIME! Welcome to the forums! Jose here, from Zwift.
Thanks for bringing this query to our attention! Jose here from Zwift.
I’m sorry to hear that you are facing issues with the avatar disappearing in the game, this usually happens for many reasons, please take a look at this thread which is similar to your case.
If you need help with anything else, don’t hesitate to contact us at support@zwift.com
Have a lovely day!