The TorBlock-Extension identifies the IP 188.8.131.52 as an TOR-Exitnode and therefore blocks anonymous write access to de-wp. The DNS-Entry for this IP is
184.108.40.206.in-addr.arpa name = proxy.nefonline.de.
In fact it is a normal customer proxy for M-NET (formerly NEFkom), a major internet provider in Bavaria/Germany. Access to it is restricted to private customers of this provider. None of the common TOR-Exit-checkers identifies this as an TOR-exit.
I became aware of this by an OTRS-ticket of a M-net customer who wanted to edit de-wp. I also live in that region also and asked some friends if they are M-NET-customers. A friend responded that he is and that he was able to confirm that false block.