The presence of Ederson in Manchester City made the transfer of Donnarumma harder. It is like a domino, just make the move and everything will follow. PSG want him to leave the club but they won't sell him for a cheap price because they will simply wait for the next transfer window in winter to have a better negotiations.
Ederson has played for Manchester City for eight seasons, and Pep Guardiola himself still has considerable confidence in him, despite rumors suggesting Donnarumma is being groomed to replace him. If PSG wait until next season, Donnarumma's contract will expire, forcing them to let the best goalkeeper go as a free agent. This situation isn't beneficial for either party, and there may still be ongoing considerations regarding the release clause and how this situation will be handled to ensure neither side is disadvantaged.