Typically, this would be a result of not having enough mowing time. Increase mowing time on the Robomow app by adding active days, more mowing sessions per day and if needed, a larger mowing hours window per day. If this is not the case here, Is the grass very high and is the RT height of cut set lower than its top 60mm (2.4 inch)? If this is the case, raise height of cut to the highest and let the RT mow for a week or so to see improvements. If the grass is much higher than the 60mm (2.4 inch) height, mow it manually with another mower or a lawn service to lower it to manageable height - 60mm (2.4 inch) or lower.