They're conflating two things. The Master playing a game with the Toymaker and losing and the Toymaker turning the Doctor's past into a jigsaw. It's not stated that these are the same thing.

That's what i thought.

You get that a lot in articles on sites like Screenrant and CBR. The writers tend to be more bothered about creating a story behind a sensational clickbait headline than bothering to double-check the facts behind what they think they are talking about. That's one of the reasons I quit reading them.

As others have stated, they’re two different points of the episode which are in no way connected despite both happening back to back in the same conversation. I believe the Toymaker’s line of “I made a jigsaw out of your history did you like it?” is what’s believed to have contradicted The Timeless Child. The Master was never “Dying and begged for his life with one final game” until presumably after Power of the Doctor.

I assumed the "jigsaw" line was about making him regenerate back into an old face. Especially since if that wasn't the Toymaker's doing, the change of clothes at the same time (and accompanying "what??") is never mentioned.

@FH2104 Well according to the page for “The Giggle” this is implied to potentially be the reason that the Doctor regenerated back into an older face:

It also answered the question as to why the Fourteenth Doctor had regenerated with the face of his tenth incarnation, with Donna believing the Doctor had subconsciously chosen the face of the Tenth Doctor so that he could not only find her again but finally settle down into a normal life.

@Grandpa Lo70 I did hear that in the episode, actually. But it didn't strike me as the reason. Just a reason.

I wouldn't trust a single word you see on Screenrant.