Quick answer: When players keep getting stuck on your tutorial, a specific step is failing to communicate what to do, an unclear instruction, a confusing interaction, or a point players can't get past. It's a clarity/design problem, not a code bug (usually). Find exactly where players get stuck (drop-off data shows the step; playtesting shows why), then fix that step, clearer instruction, better signposting, or a more forgiving design, so players can progress.
A tutorial is where you most need players to succeed, it's the start of the experience, and getting stuck there means losing players before they even reach the game. When players keep getting stuck on the same tutorial point, that point is failing to communicate or is too demanding. Because you (the developer) know exactly what to do, you can't see the problem yourself, which is why finding and watching where players get stuck is essential.
Why Players Get Stuck on Tutorials
A tutorial step where players get stuck is failing to get them to do (or understand) what's needed. Causes: unclear instruction, the tutorial doesn't clearly communicate what to do, or assumes knowledge the player doesn't have. Confusing interaction, the action required isn't obvious, or the signposting (where to go, what to press) is unclear. Too demanding, the step requires a skill or precision the player doesn't have yet. And it relies on the player noticing something they don't. Crucially, you can't see these problems yourself because you know the game, what's obvious to you (the designer) is opaque to a first-time player, so the step that traps players looks fine to you.
So a sticking point is a communication/design failure visible only to fresh players. The 'bug' is in how the tutorial reads to someone who doesn't already know the game, which is exactly the perspective you lack.
How to Diagnose It
Find where players get stuck and watch why. Drop-off data, a funnel through your tutorial shows exactly which step players fail to get past (a big drop at a step is the sticking point), turning 'players get stuck' into 'players get stuck at this specific step.' Playtesting, watch fresh players (who don't know the game) play through the tutorial, and observe where they get confused, stuck, or do the wrong thing, this reveals why they get stuck, which the data alone doesn't. Fresh-player observation is the key tool, since the problem is invisible to you but obvious when you watch a newcomer hit it.
Bugnet captures events and reports that can reveal where players drop off in the tutorial (the funnel), and player feedback, and a crash or bug at the tutorial step could even be a technical cause to rule out. But the core diagnosis is funnel data (which step) plus fresh-player playtesting (why), the data localizes the stuck point and observation explains it.
How to Fix It
Fix the specific step that traps players. Clarify the instruction, make what to do explicit and clear (don't assume knowledge), and improve signposting so the player knows where to go and what to do. Make it more forgiving, if the step is too demanding, ease it (more guidance, less precision required, allow more attempts). Add cues, visual/audio cues that direct the player to the needed action. Let players progress, ensure there's always a clear path forward (and consider letting players skip or get extra help if stuck). The goal is that a first-time player can get past the step without already knowing the game.
Then re-test with fresh players to confirm the fix, do new players now get past the step smoothly? Iterate until the sticking point is gone (the drop-off at that step disappears). Because the tutorial is the start of the experience and getting stuck there loses players entirely, fixing sticking points has outsized value, and the process, find the step (data), watch fresh players (observation), clarify/ease it, re-test, is how you make a tutorial that players can actually get through.
A tutorial sticking point is a clarity problem you can't see because you know the game. Funnel data finds the step, fresh-player playtesting shows why, then clarify or ease it and re-test.