its not how much time is spent in the gym that matters
only one thing matters and that is total pounds lifted per day
you maybe happy if you reach a new strength level for a max or complete a high volume workout. but what matters is the total number of pounds lifted in your workout was more than any other time you have lifted in your life. if you simply do not reach your personal best on total amount of weight lifted then expect the same in return. if you lifted 200 400 3000 more pounds than anyother workout you have just set a new standard for your body . in natural bodybuilding that means expect to grow and expect to make adjustments in diet to produce and even higher level next time you want to push yourself
anything less is simply maintenance and submaximal effort dont expect to get more muscle even if you did set a maximum bench press record in reality that couldve came from a number of circumstances, form, speed, not training the day before and being fully loaded for a one rep max, none of these equat to muscle gains only a consistent number of pounds lifted over a period of time does day weekly monthly ect.