Why is the ClinVar tab under the variant table not shown for all the variants even though information from the ClinVar is displayed under the tab on the right side?
The reason the ClinVar tab isn't shown is because the specific variant you are looking at has no ClinVar information. The bottom tab shows the ClinVar entry for this specific variant. The tab on the right, however, also includes ClinVar information of any other variants that overlap with the current one. So in the two examples you have shown, the selected variants have no ClinVar entries, but they overlap with other known variants which do have ClinVar information and therefore we show that on the tab on the right.
For example, chr5:39341378 G>A has a ClinVar entry and that is what is shown in the tab under the results. This variant doesn't overlap with any other known variant with a ClinVar entry and therefore it is the only variant shown in the right-hand "Clinical" tab.
However, for example the variant chr1:94467506C>T has no ClinVar entry. However, this one does overlap with other known variants which do have an entry and therefore those two variants are shown in the right-hand tab: