What to inspect
Check the base, rhizomes, roots, drainage hole, and whether cold conditions slowed drying.
Choose one evidence-based action
Separate firm healthy tissue from clearly soft rot with clean tools, let cuts callus when appropriate, and restart in a draining mix.
What not to do
Do not diagnose root rot from one mark, change several major conditions at once, or use an unlabeled treatment. Old damage may remain after the cause is corrected.
Review the outcome
Photograph the same area under similar light, record the date and intervention, then compare the boundary of damage and the quality of new growth. Escalate rapid decline or safety concerns to an appropriate professional.