Compare the first letter, the main crossing or joining strokes, the signature width, and the final movement with your source. The AI Signature Improver result can look cleaner without being useful to you. Reject it if the mark no longer feels connected to your hand, if an important letter disappears, or if a new flourish would be difficult to repeat at normal writing speed.
Next, test size. A signature that looks balanced in a large preview may become crowded when placed on a small line. View the downloaded PNG at roughly the size you expect to practice, then trace it slowly and try it again from memory. The best change is usually the one you can reproduce without thinking about every stroke.
If the direction is wrong, do not keep regenerating the same brief. Return to the AI Signature Improver workspace and switch from Elegant to Cleaner, or from Cleaner to Compact. A clearer instruction is more useful than collecting several versions that solve the same problem.