Happy 4th, my name is ***** ***** is a pleasure to work with you on this question. I have the image you sent. Let us see what we can discover about your Klee.
May I ask which auction houses you contacted?
If the Paul Klee Museum, which is the authority that most of us go to, can not find it, then the odds are low that I can. Honestly it does not look like a Paul Klee. In my opinion this was not done by the hand of Paul Klee. Even the signature is off. There are 16 other listed artists with the name of Klee and many who are willing to sign Klee even if their name is not.
You can go to customer service. I will let the moderator know.
All the best enjoy the rest of the 4th.