I'm still stuck sadly occasionally I can go further but I have no idea what's causing it.
I might have an idea as to what the problem is, what is your monitor size and what window size do you have the game at?
In the meantime you can go to C:\Users\Your User Name\AppData\LocalLow\Delusria\Salvor DEEP
Then find Playerdata.json and look for "visitedLevels" and type the number after whichever one you've discovered.