When a pool is connected to a BTCSQ node which is just synced from a clean state and the network was not producing blocks for a while during the syncing then the blocks produced by the pool dont include ATV / VTB / VBKs.
It looks like the reason is that (some) VBKs are not known by the pool and thus not is able to include ATV / VTB / VBK because when another pool mines blocks providing those blocks (or popmempool clears) then the pool is able to produce blocks with ATV / VTB / VBK.
When a pool is connected to a BTCSQ node which is just synced from a clean state and the network was not producing blocks for a while during the syncing then the blocks produced by the pool dont include ATV / VTB / VBKs.
It looks like the reason is that (some) VBKs are not known by the pool and thus not is able to include ATV / VTB / VBK because when another pool mines blocks providing those blocks (or popmempool clears) then the pool is able to produce blocks with ATV / VTB / VBK.