Why did it stall?
We find lifts that have stopped improving, check the trend isn't just noise, and look at what changed around the time progress stopped, in your training and in your eating. You get a verdict in plain English and one thing to try next.
Why: weekly chest sets went from 12 to 18 while your top-set RPE climbed from 8 to 9.5. Fatigue is probably hiding strength you've already built.
Try next: one lighter week, then 3 back-off sets instead of 5 for four weeks.
Likely 9 sessions over 7 weeks, low noise