Hi Robert,
Due to the growth of numbers in active RIPE Atlas anchors, we started involving more anchors from outside our service region in DNSMON measurements. This has a natural effect on the visualisations: the newly involved anchors don't have a measurement history yet, so they show up as "no data" before the addition.
thanks for the heads up and good to see the measurement network is growing! Could you please elaborate a bit on how you select the anchors per TLD/domain monitored and what your thoughts re stability (of the anchor set over time) and comparability (of the sets used for one domain vs another) are? I wonder whether it would scale to run all measurements from all the anchors and then only "customize" the covering set for the display. -Peter