guys how i can lose a contract by Sophie?
I've only get some general advice, not a bulletproof way to lose a contract.
1. only work the minimum required number of hours so it won't increase your success rate over the base chance.
2. pick a contract with base success chance as low as possible (30%).
3. you can cycle through contracts: you can decline the contracts given to you and ask Charlotte for new ones, up to 5 per ingame day.
Decline all contracts with a different representative and those with Sophie but a too high base chance.
Ask Charlotte for new ones until you get a suitable.
Edit:
4. Success or Failure is calculated anew for every percentage, so you can work with saves.
Take a contract and work the minimum, make a save, call Charlotte and check the next day.
If negotiation was successful, load the save, work one or two more hours (so chance increases by 1%), make another save, call Charlotte again, and check again.
That way you don't have to look for suitable contracts and work through them
I just tested myself with a 50% base success chance contract. 50% -> success; 51% -> success; 52% -> failure; 53% -> success.