Could it be root rot?
Wet soil and soft roots are useful clues, not a diagnosis by themselves.

What to look for
A plant may wilt or yellow even when the mix is wet. If you can inspect roots, compare firm roots with dark, soft or mushy sections; naturally dark roots are not necessarily rotten.
What to do
Separate the plant if infection is suspected. Remove clearly mushy roots with clean tools and use fresh, well-draining mix and a clean pot if repotting is needed. Adjust watering to the plant and watch its recovery.