When should I tell a coach that it was too much? (Barbell Gain)

After not having received a response from the official support team for over 6 days, I try my luck here:

When doing for example bench press, the coach tells me to do 10x52 kgx4 sets. In set 3, I start failing at around 5-7 repetitions, forcing me to put the bar back into the rack and rest a couple of seconds before finishing off the last repetitions. In set 4, I often have to take two short breaks during the whole set. Should I at this point tell the coach that it is too much or is it ok to do it like this?