Deja-vue … this time I had the same issue with my Contax AX as with my Contax RX some time ago.
The mirror has slipped down about 3–4 milimeters over time due to bad glue, loosing it’s adhesive quality over time.
Due to this, the mirror crashes onto the lens rear element and hangs in upper position.
I tried the same kind of repair and … let’s see how it works.
This brand was so expensive in it’s era … shame on you Contax for using such a poor glue.