Full input files can be shared by adding a link to some hosting website like WeTransfer, Dropbox or Google Drive. When the mesh contains just a few elements (like here), it might be also sufficient to use a preformatted text option like you did - then the post is not too long because there’s an additional scroll bar for the code.
I wouldn’t be very surprised if there was a bug leading to unusual behavior when coupled tem-disp step is used for purely mechanical case. I’ve encountered something like that but for opposite case (pure heat transfer in coupled temp-disp analysis): Wrong results if *Coupled temp-disp is used instead of *Heat transfer