PC Character Sheet replaced with NPC Monster

Hi all, last night I tried to drag and drop a monster (Poisonous Snake) onto a blank page.  It did not, however, appear.  More oddly, however, one of the PCs character sheets was completely replaced with the Snake’s stat block and no longer shows a PC character sheet.  The picture and token have remained the same, as does the name and Bio.  It’s only the character sheet that changed. Any idea how this might have happened and how to fix it? Many thanks in advance A

You accidentally dragged the NPC on top of the PC sheet, which added the NPC stats to that sheet. Go to the PC sheet's settings and change so it again views the PC sheet, and see how much stats are overwritten. If it's too much work to manually fix, you might want to conider doing a rollback to before you overwrote the PC character with the NPC stats.