Varitronic flywheel thread differences

Bit of a strange one, I have a Buzzetti flywheel puller and it fits an Li Varitronic flywheel I have perfectly. Just bought a GP Varitronic flywheel to go with a new crank and the same flywheel puller doesn’t fit! I’ve tried ‘persuading’ it in a little but I don’t want to bugger it up.
Anyone else had this/know what the answer is?
Anyone else had this/know what the answer is?