Bonus timing and the x50,000 ceiling
On the reels, one spin can start the Free Spins round while the spins that follow bring nothing, and nobody can predict that order. How often the bonus comes is not known in advance. The result of one session is random whatever the RTP, so a short visit may end well or badly.
Every spin on the 6x5 grid is paid under one of three RTP versions, but the reels never show which one is live. That detail sits only in the game rules, so open them before your first spin and read the figure there.
Tumbles can keep the reels moving with no limit to their count, and the top prize sits at x50,000 of your bet. That ceiling is reached very rarely, so treat it as the edge of the paytable rather than a target for any single session.