Looking at the paper, the statistical story is a bit complicated. In figure 2, the authors argue that there is a trend. But the graph seems to show the direct

Looking at the paper, the statistical story is a bit complicated. In figure 2, the authors argue that there is a trend. But the graph seems to show the direct measurements of dependent variables with confidence intervals, and they are all non-significant. This means that there is no reason to talk about a trend, especially if the difference between significant and non-significant is not significant :) [edit]: Would really have loved if they showed marginal effects here, removing the influence of control variables. But the models themselves do something else: Table 3 suggests that covid was used as a binary variable to test for. So they are comparing pre-covid to covid-time and see a significant result there. Methodologically, it doesn't seem like a bad design, but the sample size is really a bit small to have sufficient power. Apart from that, the effect size of covid (31) seems really high, but developmental psychology is not my field so I can't say anything about that.