This is a 2013 XC60. For a while now the rear driver door would intermittently unlock / lock. The fix? the door latch module. Of course, from Volvo the part is like $300. But, aftermarket parts are available and do seem to be reliable enough to use for 1/4 of the cost. So, if you have this issue, give this a go!
){kind=link}
If you have any questions about the parts or process, feel free to drop a comment. I read everything.
A few weeks in with this part and it's still working well!