Radial pebble mass flux (solid lines, left-hand axis) and cumulative pebble mass (dashed lines, right-hand axis) in the inner disc as a function of time for the five stellar masses used in this study. After around 0.1 Myr, the pebble formation front reaches the outer edge of the disc, after which the slope of the pebble mass flux becomes significantly more negative. The disc around the 0.09 M_⊙ star is weighted as 10% of the stellar mass, while all others are weighted as 5% (see the discussions in Sects. 3.1 and 4).