Why my level didn't change after a match

Level

You played, you won or lost, and your level is the same. It is almost always one of the reasons below; the result stays in your history either way.

When a result does not move your level

The match was not competitive. A friendly or open-play match never moves your level (see friendly matches and your level).
The result is not confirmed yet. It only counts once the other team confirms it, once the club confirms it automatically when its window runs out (if the club turned that on), or once an operator settles it. If nobody answers, the result waits: it is never accepted in silence.
The result was rejected. If a player disputes it, it goes to review and nobody's level moves until an operator resolves it.
Someone had no level when it was played. If even one of the four players had no level in that sport at the time of the match, the result moves nobody's level. This is not revisited later: if you got your level (for example through the level questionnaire) after you played, that match does not count even though you have a level now.

Padel and tennis: a normal set ends 6-0, 6-1, 6-2, 6-3, 6-4, 7-5 or 7-6. A 6-5 or 6-6 is not a finished set and cannot be entered. Short sets to 4 games (4-0, 4-1, 4-2, 5-3, 5-4) are also accepted, and so is a super tie-break to 10 points, won by 2 (10-8, 12-10), as the deciding set when it is 1-1.
Pickleball: each game is won at 11, 15 or 21 points, by a margin of 2.
A winner and no extra sets: the match ends as soon as one side wins the majority of sets, so a set entered after that is refused. A tie is not a valid score either.

If the other team entered the wrong score, propose the right one: correcting a match score.
If the match was friendly by mistake, ask the club staff to mark it official. They can do it up to 14 days later, as long as the result is not disputed or already counted.
If you still do not understand what happened after checking this, open a support case. For the big picture, see how my level goes up or down.