Temporal evolution of the semi-major axis (bottom panel) and the eccentricity (top panel) of a single low-mass 0.1 M_⊕ embryo embedded in the gas and pebble discs, for four different discretisations in space, namely 512 × 768 cells in r and θ (i.e. a very low resolution), 1024 × 1536 (low), 2048 × 3072 (moderate), and 3072 × 4096 (high). Theamplitudes eccentricity oscillations are approximately the same for all cases, even though the torques have much larger amplitudes for very low and low resolutions. To obtain a correct value for the migration rate d a∕d t, one would need the moderate resolution at least. The rate da∕dt is about three times as large for the low resolution.