Something internal has failed, permitting the latch to become free.
The first step is to remove the handles, then to remove the latch assembly.
Once the latch assembly is removed from the door pocket, examination of the problem(s) may be performed.
It might be that repair is possible.
Here is a replacement. Looks to be correct.
https://www.fpmarine.com/Mobella-latch-engine-p/ma-brassengine.htm
