It looks like something foreign is in the light path and blocking the eyepiece view of the full primary mirror.
Place your eye at the focuser tube and see if you can see the entire primary mirror reflected in the secondary.
- Is the secondary correctly aligned under the focuser to catch the full light cone of the primary?
- Is the focuser draw tube extending too far into the ota tube and intruding into the light path?
Another possibility is that the primary mirror mount clips are too tight, but if the chopped off part is really a straight edge this isnt the likely cause.