You might want to try putting the battery in backwards for a sec, on the off chance it helps. Sounds ridiculous I know but there are a few google results saying 4iiii asked them to try this and it apparently working (not neccessarily this specific issue though)..
You might want to try putting the battery in backwards for a sec
This is exactly the step that has sorted out my 4iiii Precision, which also would not calibrate. There wasn't any sign of water ingress, but the seal had split, so I'm guessing that's what caused the issue originally.
You might want to try putting the battery in backwards for a sec, on the off chance it helps. Sounds ridiculous I know but there are a few google results saying 4iiii asked them to try this and it apparently working (not neccessarily this specific issue though)..