Samsung WD80J6410AX/EU Door Lock problems

So my Samsung washing machine has started having issues with the door locking.

When you close it to start the cycle it will click repeatedly every few seconds for about 30 seconds and then will sometimes start. Except that it’s not locked and I can still open the door.

I presumed that the locking mechanism had gone somehow so I ordered a replacement and changed it out but it’s still doing the same with the new part. Any suggestions for what to try next? I’ve been looking at the door trying to work out how to access the metal spike in case that’s somehow become unseated or something but it looks fine.