Auction houses have the right to block bidders for their auction. Usually the reason is that invoices from previous auctions have not been paid.
If the auction house wants to block bidders, it has to choose from a list of predefined reasons. The list is divided into two levels, one private and one public. A non-payment case would be on the public level and therefore visible to other auction houses. On the private level, reasons such as debt collection proceedings or private disputes are indicated.
If you believe that your account has been unjustly suspended and would like to resolve this, please contact the auction house directly.