The 987/997 has a flaw where the internal door handle mechanism can break, leaving the handle inside functional but floppy.
Fortunately, the parts are not expensive and the fix is pretty straightforward--pull the door card off, put in the new mechanism, and away you go. Removing the door card takes trim pry tools, some patience, and a Torx T-20 and T-30 bit.
The interior part was only about $25, but I took the opportunity to swap the silver plastic handle inside, as well, since mine was kind of hacked up and scratched. That cost $165, for some reason, but was purely cosmetic.
In fact, once I had the door apart, I couldn't find a broken piece. I suspect that like the poster
here, the spring on the latch had just slipped. But since I had the new part and it was only $25, I swapped it in anyway.